Defining what a successful SUPER-conductor for a magnet is, isn’t easy. It is often underestimated to what extend the type of magnet and its application are strongly determining the conductor requirements. Whether it is a one-off magnet where cost is not an issue, a quasi-commercial small series, or a long-term commercial production of magnets, is crucially influencing the conductor choice....
We focusing on investigating the protection of meter-class REBCO no-insulation (NI) coils applied in next generation high-field magnetic resonance imaging scanners. In order to address the issue of controllable contact resistance, we proposed a method is based on an external variable resistance, which is paralleled with an NI coil to realize the controllable contact resistance. It can maintain...
Cryogenic bypass diodes have been installed in all superconducting dipole magnets (1232) and all main superconducting quadrupole magnets (392) of the Large Hadron Collider (LHC) at CERN, and operated during the physics runs since 2009. The by-pass diodes are a fundamental ingredient of the quench protection system for those main dipoles and quadrupoles magnets. Diodes are located inside the...
In general, superconducting magnets operate at high currents, and excessive joule heating due to high currents can damage the magnet when quench occurs. Therefore, a quench protection system that can reduce the magnet current quickly is required when the normal zone occurs in the magnet. For this reason, several quench protection methods are being developed to rapidly reduce the current. In...
The quenching of superconducting magnets is one of the key issues affecting the safe and stable operation of superconducting devices. The effect of Magnetic flux jump and electro-magnetic stress leads to local critical current drop, continuous accumulation of heat of joint resistance, failure of refrigeration equipment or other auxiliary equipment, etc. These effects may cause quenching of the...
Recently, a new quench protection system using capacitor and switches has been announced to rapidly extract energy from high temperature superconducting (HTS) magnets. When a quench occurs, the quench protection system activates four MOSFET switches in sequence, and the energy stored in the magnet is extracted through an external resistor through a capacitor. In previous studies, the system...
Quench protection is critical for superconducting systems, especially those containing enough energy to damage the system during quench. We propose a new quench protection approach for multi-coil low temperature superconducting (LTS) systems that minimizes the number of protection components that must be activated during quench. In this approach, the electrically (and probably also...
Previously, we verified the feasibility of using a Raman-based distributed temperature sensor (RmDTS) system to measure a no insulated (NI) high temperature superconducting (HTS) coil temperature variation during an overcurrent induced quench event. In addition, to reduce the temperature response time of the RmDTS, we further optimized the whole measurement system. However, the combination...
When a quench occurs in a high field no-insulation (NI) high temperature superconductor (HTS) magnet that consists of a stack of double-pancake (DP) coils, a large amount of current is often induced in an NI DP coil that is electromagnetically coupled with neighbor DP coils. Depending on the strength of external magnetic field, the large induced current leads to an excessive magnetic stress...
HTS coils wound with insulated wires are actually quenched, even though HTS wires have a high quench margin and can be easily damaged, if the quench protection system does not work properly, especially in the case that current density of the magnet wires is high, It should be noted that the training effects as in LTS magnets have not been observed in HTS magnets and that damaged HTS magnets...
The superconducting wires have been developed for high field magnet, transformers, motors and so on. The quench detection and protection system are essential for safety operations of the HTS facilities. The high voltage signal conditioner (HVSC) method is generally used for the quench detection and protection, however, especially for high voltage operation magnet such as international...
The Large-scale Superconductor Test Facility (LSTF) serves as an important part of superconducting magnet load testing for fusion research which concerns about the nuclear energy producing. During the testing process, quench protection (QP) is indispensable for protecting the load from being overheated damaged. In this paper, a compatible and flexible QP framework is put forward to meet the...
Electromagnetic forming (EMF) processes of sheet metal are used to manufacture several components in modern industry. The EMF process is a highly nonlinear phenomenon and its understanding is a complex task due to the coupling of the electrical, magnetic, thermal and mechanical problems. The generated electromagnetic forces in this process are directly correlated to the resulting deformed...
Rare earth barium copper oxide (REBCO) coated conductor has been promising conductor for the design of high field magnets due to its high strength, high critical current and high critical field. However, high temperature superconducting (HTS) magnets are challenging to protect due to slow normal zone propagation velocity (NZPV). No-insulation (NI) winding technology has been demonstrated to...
As part of the design justification of the ITER magnet system and in preparation of the commissioning activities, the heat deposition on the ITER cold structures has been computed in order to generate input loads for subsequent thermo-hydraulic analyses, which are essential for the assessment of the temperature margins of the superconducting cables. The Finite Element model of a 40 degree...
In order to control and reduce the vibration of magnetically controlled reactors(MCRs) with gaps core structure, accurate stress computation should be carried out. Previously, researchers proposed a finite element model for reactors core stress calculation considering Maxwell stress theory and magnetostriction effect. Giant magnetostrictive materials are used to be filed into the gaps to...
ABSTRACT: The large range of length scales presents within superconducting magnet and its heterogeneity, a straightforward numerical simulation of a magnet, considering all details of the microstructures would cost enormous time, so incorporation of the multiscale approaches into computational models can facilitate the numerical analysis. Additionally, the superconducting magnet with high...
Computational modeling of superconducting magnets allows for predicting and understanding magnet behavior. The commercial software ANSYS is a widely used finite element software for mechanical, thermal, and electromagnetic modeling of superconducting magnets. ANSYS also allows its user to create custom elements by programming the elements’ properties and its finite element matrices. These user...
FEM simulations are a standard step in the design of accelerator magnets. It is custom for accelerator applications to characterize the field quality in terms of field expansion coefficients. Expansion coefficients are usually calculated by means of a Fourier transform of the local FEM solution evaluated at points on a circle (2D) or cylinder (3D case). The accuracy of the coefficients...
Kai Zhang, Sebastian Hellmann, Marco Calvi
Paul Scherrer Institut, Villigen, CH
Lucas Brouwer
Lawrence Berkeley National Laboratory, Berkeley, CA
Abstract – In this work, we will introduce the feasibility of using A-V formula in ANSYS to simulate the magnetization process of HTS bulk materials. The iterative algorithm method (IAM) based on ANSYS APDL is firstly developed to...
Characterizing the magnetic properties of industrial magnetic materials has great significance on the development of transformers, motors and other electrical equipment. Recently, high-frequency and high-power density electrical equipment has attracted more attention. As the frequency is getting higher and higher, the losses of the magnetic core are much higher than that in the power frequency...
The High-Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP) is approaching the production phase of the US-contributed Q1 and Q3 Interaction Region Quadrupoles (MQXFA). The structures for the MQXFA prototypes were design and inspected by the US-LARP (LHC Accelerator Research Program), AUP developed criteria, which will be used for the pre-series structures. As the first two full-length...
In the frame of the HL-LHC upgrade, assemblies of two 5.5 m long 11 T Nb3Sn dipoles (MBH) are expected to replace 8.3 T NbTi LHC main dipoles (MB). Double and single aperture models, each 2 m long, were built and cold tested in operational conditions. The models have design features that are verified during these tests to provide feedback for the technology development of 5.5 m full-size...
The HL-LHC Project at CERN requires the installation of 11 T Nb3Sn dipole magnets to upgrade the collimation system. Given the high operating field and current density, the quench protection of these magnets is particularly challenging. The baseline protection scheme of the 11 T dipoles is based on the quench heaters technique.
Dedicated quench tests were carried out at CERN on short samples...
In the CERN Large Magnet Facility (LMF), the series production of the Nb3Sn-based 11 T dipole magnets is currently ongoing. Results from magnet tests and observations regarding the conductor irreversible stress limitations have shown that a uniform and well-defined pre-load is crucial. The collaring force in the assembly is adjusted by the thickness of a longitudinal shim derived from the...
In the framework of the HiLumi project, the present LHC low-β superconducting quadrupoles will be substituted with more performing ones, named MQXF. MQXF will have high peak-field on the conductor (~12 T), therefore the Nb3Sn technology is needed in order to reach the target performance.
One of the main technological challenges for the Nb3Sn magnets is the coil fabrication: due to the...
The CERN Large Magnet Facility (LMF) is currently producing 5.5 m long 11 T dipole and 7.2 m long MQXFB quadrupole coils for the HL-LHC project. Both coil types are fabricated with Nb3Sn conductor and therefore produced based on the so-called wind and react process. These coils require a vacuum impregnation process to form the final electrical insulation.
The paper will present the...
The United States High Luminosity Large Hadron Collider Accelerator Upgrade Project (US-HL-LHC AUP) is designing and fabricating 11 Q1/Q3 cold masses for the interaction regions of the LHC. Each cold mass contains two 4.2 m quadrupole magnets. The Nb3Sn quadrupole magnets operate in superfluid He at 1.9 K with a nominal field gradient of 132.6 T/m. The design and fabrication of the through and...
Abstract— A future Electron Ion Collider (EIC) may require high gradient superconducting quadrupole magnets for final focusing of the hadron beam in the interaction region. Due to the closeness to the beam collision point and the narrow 25mr crossing angle these high gradient magnets will reside in close proximity to electron beam magnets, thereby requiring a very compact support structure in...
IMP is developing a Nb3Sn superconducting magnet system for a 45 GHz electron cyclotron resonance (ECR) ion source. To achieve this complicated and difficult Nb3Sn magnet, a prototype with identical cross section but half length of the magnet is proposed. Recently a single sextupole coil about 0.5 m long has been fabricated and tested. The coil has a bore size of 200 mm and was wound by using...
Circular Electron Positron Collider (CEPC) with a circumference about 100 km, a beam energy up to 120 GeV is proposed to be constructed in China. Most magnets for CEPC accelerator are conventional magnets, except some superconducting magnets are required in the interaction region of CEPC collider ring. High gradient final focus doublet quadrupoles QD0 and QF1 are required on both sides of the...
Due to the small size and low power consumption, compact superconducting cyclotron are suitable to be installed in hospital for cancer therapy, which becomes a research hotspot in recent years. China Institute of Atomic Energy has been developing a 230MeV compact superconducting cyclotron CYCIAE-230 to meet the demands of proton therapy in China. Accelerator physics design requires a strict...
A 230 MeV superconducting cyclotron CYCIAE-230 is being constructed by the China Institute of Atomic Energy. The technology of magnetic field measurement and amending processing is the primary task to realize the isochronous acceleration of cyclotron. The CYCIAE-230 has higher magnetic field, higher field gradient and dense rotation orbits. Therefore, the isochronous field and resonance...
Proton beam with an average power of 5MW-10MW have important applications in particle physics towards the intensity frontier, as well as in the advanced energy, and material science. The fixed field alternating gradient (FFAG) accelerator combines the advantages of existing accelerators, which has a higher limitation of beam energy than high power cyclotron and has a higher beam-to-grid...
This paper presents a 3D mechanical analysis study of the mechanical behaviour of the complete magnet structure of the Block-coil Dipole option for the future Circular Collider. The analysis includes three steps: (i) pre-loading with bladders and keys, (ii) cooling down from room to operating temperature, (iii) ener-gization at operating temperature. The main objective of the 3D optimization...
Superconducting accelerator dipole magnets, based on Nb3Sn technology, with a nominal operation field of 16 T in a 50 mm aperture are being considered for the Future Circular Collider (FCC) with a center-of-mass energy of 100 TeV and a circumference in the range of 100 km, or an energy upgrade of the LHC (HE-LHC) to 27 TeV. To demonstrate the feasibility of such magnets, a twin-aperture 16T...
The Italian Institute for Nuclear Physics (INFN), in collaboration with CERN, is going to build the short model in Nb3Sn of the main bending dipole for the Future Circular Collider (FCC). The magnet will be developed on the basis of the baseline design presented in the FCC Conceptual Design Report (CDR) in the end of 2018. The magnet is based on cosine-theta design, with an internal aperture...
The forecast hadronic synchrotron studied in the FCC-hh program aims to reach 100 TeV center-of-mass collision energy using 16 T bending dipole magnets along a 100 km long ring. Gaining such magnetic field occupying a reasonable volume requires new technologies to be tested and validated on demonstrators. In collaboration with CERN, CEA is developing F2D2, the FCC Flared-end Dipole...
As part of an international collaboration, CERN has recently published a Conceptual Design Review of the Future Circular Collider (FCC), a proposed particle accelerator to succeed the LHC. Under the options considered, a proto-proton accelerator with collision energies up to 100 TeV, would require approximately 4’500 Nb3Sn superconducting dipole magnets operating at 16 T fields, installed in a...
We report the design for a hybrid block-coil dipole using advanced cable-in-conduit windings. The dipole is designed for use in the arcs of an energy-doubling lattice in the LHC tunnel.
The block coil design facilitates configuration of hybrid sub-windings of Bi-2212, Nb3Sn, and NbTi, each operating to the same fraction of critical current.
The cryogenics utilizes supercritical helium,...
Aiming to develop a combined superconducting magnet for a fourth-generation ECR source operating at 45 GHz at the Institute of Modern Physics (IMP) in Lanzhou of China, a significant gain in performance can be achieved by using Nb3Sn to allow solenoids and sextupole coils to reach a high field of 12 T. In consideration of special design of the sextupole-in-solenoid shape, the supporting...
The first 100-m iron-based superconductor (IBS) tape was produced by Institute of Electrical Engineering, Chinese Academy of Sciences (IEE-CAS) using the powder-in-tube technique in 2016. Since then, the development of IBS tape provides an opportunity to propel the practical IBS application. In this study, the world first IBS racetrack coil was made using a 100-m 7-filamentary Ba1-xKxFe2As2...
The Institute of High Energy Physics (IHEP, China) has been engaged in the development of shell-based dipole magnet with common-coil configuration for the pre-study of Super proton-proton Collider (SppC) project. The first subscale magnet LPF1, with two Nb3Sn coils and four NbTi coils, reached a bore field of 10.2 T at 4.2 K. Then a higher safety margin model has been proposed as LPF2, which...
MQXF is the Nb3Sn Low-β Quadrupole magnet that the HL-LHC project is planning to install in the LHC interaction regions in 2026 to increase the LHC integrated luminosity by about a factor of ten. The magnet will be fabricated in two different lengths: 4.2 m for MQXFA, built in the US by the Accelerator Upgrade Project (AUP), and 7.15 m for MQXFB, fabricated by CERN. In order to qualify the...
Abstract: Based on the Agreement of Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) and Ministry of Science and Technology of China during the Thirteen Five-Years Plan (so called 13∙5 plan), A dedicated test complex of superconducting magnet for China Fusion Engineering Test Reactor (CFETR) will be constructed in Hefei, China. A pair of high temperature superconducting (HTS)...
Engineering design of China Fusion Engineering Test Reactor (CFETR) Central Solenoid (CS) coil had been started in Institute of Plasma Physics, Chinese Academy of Sciences. The highest field of CS coil is 17.2T when the running current is 60KA. CS magnet system mainly consists of 8 Nb3Sn coils compressed with 8 sets of preload structure. The functions of the preload structure are to apply an...
The Central Solenoid Model Coil (CSMC) project of CFETR that began in 2014 is devoted to develop and verify the manufacturing and testing technology of the large-scale superconducting magnet. The main manufacturing processes for the coil are verified by the mockup coil’s fabrication. For now, the winding for the Nb3Sn inner and outer coils are finished and preparing for its heat treatment, and...
In order to further study fusion, China National Integration Design Group designed and developed a new superconducting magnet tokamak device, China Fusion Engineering Test Reactor (CFETR). As one of the most important components of the CFETR, the CS coil will be constructed to create, form and maintain a stable operation of the plasma. The latest CFETR CS magnet system design requirements are...
Abstract:The China Fusion Engineering Test Reactor (CFETR) Central Solenoid Model Coil (CSMC) is being designed and fabricated by the Institute of Plasma Physics Chinese Academy of Sciences. In order to validate structure strength and reliability of the CS Model Coil, model analysis and seismic response analysis have been carried out. Firstly, the paper established the CFETR CSMC model by...
The design of the China Fusion Engineering Test Reactor (CFETR) has been updated since the end of 2018, the major and minor radius are enlarged to 7.2 m and 2.2 m. The CFETR magnet system consists of 16 TF coils, a eight-module CS coil, 6 PF coil and 18 CC coils. It is decided recently that a TF coil will be designed and fabricated from 2019 through 2024 by the Institute of Plasma Physics...
The CSMC are major components of CFETR to generate the magnetic field for Simulating the Central Solenoid coil manufacturing process.Several trials were performed to qualify and optimize the heat treatment procedure of the Central Solenoid coil. In the trials, gas replacement, temperature controlling, protective gas flow controlling, coil fixture, and assembling procedure were performed to...
The central solenoid (CS) of JT-60SA has four electrically independent modules, and one module is 52-layer coil combined 6 octa-pancake coils and a quad-pancake coil vertically. The CS module is supplied with current through the room temperature busbar and current feeder of the superconductor. The maximum voltage between the CS module terminals is designed to be 10 kV, the voltage between the...
The construction of a full-superconducting tokamak referred as JT-60 Super Advanced (JT-60SA) is in progress under the JA-EU broader approach projects. The magnet system of JT-60SA consists of 18 toroidal field (TF) coils, 4 modules of central solenoid (CS) and 6 equilibrium field (EF) coils.
CS modules are manufactured one by one, then 4 modules are stacked. Finally, the pre-compression are...
In recent years, axial flux hybrid-excited permanent magnet machines with high power density, high efficiency and compact structure have the potential application prospect in the electrical vehicles. Besides, due to the rare earth resource crisis, the less-rare-earth permanent magnet machines have been taken much attention. In this paper, an axial flux partitioned stator hybrid-excited...
In case of Surface-mounted Permanent Magnet Synchronous Motor(SPMSM), PMs are attached to the surface of laminated core. They are connected by adhesion and magnetic force. However, in order to withstand rotation of the motor, thousands of revolutions per minute, rotor-teeth between PMs are essential to hold them strongly in position.
The rotor-teeth are also ferromagnetic material, they...
Recently, much research has been conducted on non-rare-earth magnet motors due to limited reserves and high prices of rare-earth materials. Among them, a magnetic flux concentrating motor using a ferrite magnet is being commercialized in many parts. However, it is disadvantageous to high-speed operation due to the structure of the rotor. In this paper, we propose a hybrid structure of a...
As the price of rare earth permanent magnet (PM) is very high, developing of high performance electrical machines with non rare earth PM is have received extensive attention, and synchronous reluctance machine (SynRM) has show good performance when comparing with other electrical machines. The torque ability of SynRM is proportional to its saliency ration which is determined by the rotor...
Post-assembly magnetization is usually used in manufacturing process of high-speed permanent magnet(PM) rotors. This paper reports the optimization and test of a saddle-shaped post-assembly magnetizing coil for a 300kW 2-pole high-speed permanent magnet (PM) rotor. The required magnetizing space is 85 mm in diameter and 200 mm in length. A saddle-shaped coil structure is proposed, which...
Weihua Huang, Junchen Zhao, Jin Wang*, Libing Zhou
State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Schoole of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Abstract
With the increasing demand for electric vehicles, electric power steering (EPS) system is in the spotlight. The EPS system has high...
The vibration occurring in an electric motor can be largely divided into mechanical vibration due to nonaligned bearings and shafts, and electromagnetic vibration by the electromagnetic force. For existing industrial electric motors, the mechanical vibration associated with the life of the motor was the most important concern. However, in recent years, electric motors—such as the ones used for...
In order to cope with environmental pollution caused by the recent increase in electric power consumption, 'Minimum Energy Performance Standards(MEPS)' is being implemented in developed countries. MEPS is a policy to regulate the efficiency of the motor, which is a large part of the industrial power consumption, and it is a policy to prohibit the use of low efficiency induction motors....
[Introduction]
Permanent magnet (PM) motors, which have various advantages such as the wide operation range and high power density, are widely developed in various industrial fields such as automobile, aerospace, home appliance, defense industry and so on. The study and development of the slot-less PM motor is actively underway as the servo and driving motor, because it does not have teeth...
The recent next-generation railway vehicles are aiming at energy saving and weight lightening and IPMSM(Interior Permanent Magnet Synchronous Motor) with a more improved efficiency and weight to output ratio than induction motor when rare-earth permanent magnet with high energy density is applied to synchronous motor have been developed a lot. Interior permanent magnet synchronous motor, used...
[Introduction]
It is necessary to develop a motor with high output density, high efficiency, and high control accuracy in various industries like automobiles, robots and defense industry. Among the various types of motors, Slotless permanent magnet (PM) motors having relatively structural and electromagnetic advantages over slotted motors have been continuously developed for the precise...
This paper presents a comparison of cylindrical and plane air gap magnetic couplings in which the tile permanent magnet polarizations can be either radial or tangential or axial.The expressions of the torque transmitted between the two rotors of each coupling are determined by using the finite element method . For this system, a Halbach permanent magnet (PM) array structure is applied as a...
- Introduction
Recently, a new types of high efficiency motors are increasingly receiving attention because of the minimum energy performance standards (MEPS). A permanent magnet assistant synchronous motor (PMA SynRM) has high efficiency since it does not have copper loss of rotor in comparison with induction motor. Therefore, PMA SynRM receive attention as the new type of high efficiency...
- Introduction
Compared to three-phase motors, multi-phase motors have higher torque density, smaller torque ripple, and higher reliability. In addition, multi-phase motors can be operated with other healthy phases, even if one phase fails. Therefore, with the increase in industrial applications that require fault-tolerance and continuous operation, such as EVs, military, and aerospace,...
In this paper, the influence of the change of eddy current loss of the IPMSMG (interior permanent magnet synchronous motor generator) for automotive ISG according to magnet lamination direction on the Demagnetization characteristics and vibration was studied. Reduction of the eddy current loss reduces the heat generation in the magnet and affects the demagnetization characteristics and...
This paper presents the optimal design method of cage-bars in a single-phase line-start permanent magnet synchronous motor considering the starting torque and magnetic saturation. This method consists of two procedures. First, the basic design of cage-bars is made by analytic method of a single-phase induction motor. In this case, the equivalent magnetic circuit method is used but this method...
In semiconductor photolithography equipment, high productivity and nanometer precision of the motion stages are combined to enable shrink in chip dimensions at reasonable cost. High-force density linear and planar motors drive the stages which carry the reticle mask and the wafer with acceleration levels of multiple tens to hundreds of m/s2. Superconducting actuation might be a next step to...
This paper proposes a design and optimization of ferrite assisted synchronous reluctance machine. SRM(Synchronous Reluctance Motor) could be applied in electrical vehicle traction due to its salient advantage. SRM is cheaper than traditional PMSM(Permanent Magnet Synchronous Motor) because it needs no permanent magnet or some ferrite(in Permanent Magnet Assisted Synchronous Machine), which...
Generally, when designing an electric device, the harmonic components in the electric angle of the MMF do not generate the average torque, so only the fundamental component in the electric angle is considered. Also, the back EMF and the torque ripple include only the harmonic components based on the electric angle. Therefore, the conventional MMF wave equation considers only the harmonic...
An important index in determining the performance of a permanent magnet synchronous motor (PMSM) is the maximization of using the permanent magnet (PM) inserted in its rotor. Thus, a process that verifies the demagnetization of PM is generally included in a design process of PMSM. However, the magnetization, which is also one of the important indexes in the design process, has not been much...
The Axial Flux Permanent Magnet Synchronous Motor (AFPMSM), manufacturing 3 Dimensions are limited in few ways. 3D modeling is less mass-produced with high cost of unit production because stator must roll up the amorphous electrical steel plate or be molded. The study shows AFPMSM with 3D printing technique cannot be materialized in existing motor. Under the same conditions of motor design...
In this paper, the demagnetization and vibration characteristics of a 48V 5kW BLDC ISG motor generator are analyzed according to the magnet segments. Particularly, permanent magnet is divided into 3segments and 7segments as a comparison model. According to the operation characteristics of the ISG, the driving area was divided into three areas: motoring 3000rpm, power generation area 4000rpm,...
Permanent magnet synchronous machines (PMSM) with fractional-slot concentrated winding (FSCW) configuration are featured with short end windings, low mutual coupling between phase windings, high self-inductance, high slot fill-factor, reduced losses and easy and cheap manufacturing process, which makes them best choices for many applications. Based on these merits, a novel type of FSCW...
Torque motors for servo valves were created about 50 years ago, and they are used in several military and aerospace applications. Servo valves, which are now widely used in the general industrial and simulator fields, are still the beginning of fusion devices located at the top of hydraulic devices can do. A common torque motor uses a feedback spring for the rotor's alignment. This is a...
Under the construction schedule of the next generation of Circular Electron-Positron Collider building in China, the cryogenic conception design of the detector magnet is completed, and some related preliminary research works have come out good results as well. A network of LHe tubes in the thermosiphon circulating mode, which is attached to the extemal coil wall, is used to cool the coil....
The 3rd generation synchrotron light source will use a lot of insertion device, such as SC wiggler and SC undulator, to generate synchrotron radiation photon. The cryostat of 3W1 SC wiggler magnets have been finished assembling and cryogenic testing, the test results show that in the normal operating mode (no power failures, unexpected quenches etc.) the cryostat work with close to zero liquid...
The high temperature superconducting (HTS) magnets cooled by solid nitrogen (SN2) are of great merits of lower thermal temperature gradient, better thermal uniformity and thermal stability. However, the existing cooling system cannot provide a long-term stable low-temperature circumstance for HTS magnets due to significant heat load, since they are not specially designed for the SN2. Meantime,...
The cryogenic system plays a vital role in the development of superconductivity. In a sense, superconductivity would be in more widespread use now if it were not for the problems associated with the cryocoolers needed to cool the superconducting devices or facilities. For a variety of high-Tc superconducting applications such as transformers, fault current limiters, motors, generators, power...
A conduction-cooled HTS magnet is designed and tested to produce AC magnetic field of maximum 4 T for an adiabatic demagnetization refrigerator (ADR). The magnet equipped with extensive copper thermal drains is conductively cooled by a GM cryocooler to approximately 5 K and stably generates alternating magnetic field between 0 and 4 T at 0.2 T/s. The fastest ramping rate that dictates the...
The design of a large purpose built cryogen-free magnet is reviewed. The system has been manufactured for the Fundamental Neutron Physics Beamline (FNPBL) at the Spallation Neutron Source (SNS), Oak Ridge, Tennessee.
The magnet system will house a custom spectrometer and be used to measure a, the electron-neutrino correlation parameter, and b, the Fierz interference term in neutron beta...
Abstract
High temperature superconducting (HTS) taped stacks have broad application in magnetic levitation because of uniform induced current distribution, good heat dissipation and preferable mechanical properties. Configuration of the stack has a great influence on the uniformity and strength of the trapped magnetic field. In this paper, 3D modeling and experiments of HTS taped stacks with...
Abstract-Stacks of commercial high temperature superconducting (HTS) tape can be magnetized to act as strong magnets for magnetic levitation. Based on our laboratory's high temperature superconducting magnetic levitation platform, in this paper, commercial superconducting tapes are used for stacking to replace the superconducting bulks. We stacked new model round bulk with a diameter of...
The top seed method and the interior seed method are com-bined for the purpose of improving the electromagnetism of the superconductor by removing defects such as processing and cracks in the YBaCuO crystal. The top seed melt growth process is widely used as a process for growing superconducting bulk.When measuring the magnetic levitation force on the upper surface of YBCO superconductor, the...
Dynamic behavior with the hysteresis of the levitation force of a magnet-superconductor system is investigated with application of an alternating magnet field. The effect of a resonance swinging and break-off of the samples from the levitation level is found. Subharmonic resonance associated with the nonlinear of levitation dynamics is shown to the system. The critical amplitude vs. the field...
The levitation properties of permanent magnet-superconductor systems have been studied for a long time. Recently it has been demonstrated extensive possibilities of application of stacks, slabs and windings from HTSC tapes for levitation systems.
In this work a design of a superconducting passive magnetic levitation bearing on the base of HTSC flexible tapes is proposed and implemented. The...
The magnetic gear can prevent the noise, vibration, and damage due to the noncontact drive.
Many papers have been published with regard to the design of magnetic gears. However, most design methods in the study only considered magnetic properties. The structure of the magnetic gear has two voids, and permanent magnets are located on the inner and outer rotor. And, a fixed-pole is located...
At temperatures near absolute zero, the materials used in the superconducting magnetic suspension device are chemically inactive and the electrical losses are very low, which makes the device have a high accuracy in measuring angular velocity and angular displacement. In order to determine the accuracy of the device, it is necessary to carry out the drift test for the device. One of the...
Magnetic gear which is capable of non-contact transfer torque has replaced mechanical gear and has advantages of high-efficiency and improved reliability. Common electrical devices, such as motors and generators, have a single air gap. However, there are two air gaps in the magnetic gear, and a laminated structure called a pole piece is arranged between the two gaps at regular intervals in the...
Because typical electrical devices cannot be driven without a power converter, the use of gears is essential. Various studies have focused on magnetic gears without mechanical losses. In certain linear motion systems, such as wave energy power generators, using linear gears is inevitable. The most important aspect of gears in linear systems is manufacturing feasibility. Recently, research on...
A magnetic bearing uses eddy current sensors or Hall sensors to detect rotor displacement, which results in the problems such as large volume, increased cost and reduced reliability. Therefore, the research on self-sensing methods of rotor displacement for magnetic bearings has theoretical and application value. State estimation method and parameter estimation method have problems such as...
Besides the advantages of the conventional magnetic bearings such as high speed and high precision, AC magnetic bearings also have strengths such as small size and low cost because of the use of mature technology of inverter driving. Therefore, AC magnetic bearing has potential application prospects in industrial manufacturing, aeronautics and astronautics, wind power generation and other...
With the development of energy saving and advanced equipment in the modern industry, the requirement of high-speed and high-power density motor are developing. Compared with the conventional bearings, magnetic bearings have the advantages of no friction, no lubrication and sealing, high speed, high precision, long service life. Thus, Magnetic bearings have been widely used in high-speed...
Comparing with traditional bearings, magnetic bearings have the advantages of no friction, no lubrication, high speed, high precision, long life, etc.. Therefore, magnetic bearings have broad application prospects in the fields of flywheel energy storage, wind-generated electricity, high-speed machine tool and so on. The six-pole hybrid magnetic bearing is driven by a three-phase inverter,...
It is crucial to calculate the levitation force in the designation of superconducting magnetic bearing (SMB). Due to the external disturbances or the time-variable load, it is necessary to study the dynamic levitation behavior in order to ensure the stable levitation of SMB. In this paper, we investigate the dynamic behaviors of the axial levitation force for the radial-type SMB. By adopting...
We are studying magnetic bearings combining multiple cubic superconducting bulks. Calculate the placement by optimum calculation so that the fluctuation of the trapped magnetic flux distribution is minimized according to the cubic bulk arrangement and decide the optimum arrangement for the magnetic bearing.
In this experiment, eight magnetic cubic blocks were arranged in a square to...
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INTRODUCTION
Recently, magnetic levitation techniques have been developed for various fields such as energy storage flywheels and magnetically levitated vehicles. Thus, there are many reports about levitation techniques using high critical temperature (Tc) superconducting magnetic bearings (SMBs) composed of superconducting (SC) bulk and permanent magnet (PM). In this paper, new SMBs...
Studies on coaxial magnetic gears (CMG) have been actively conducted. CMGs can replace mechanical gears as they can perform noncontact power transfer, thereby minimizing loss and damage from friction.
However, the permanent magnet eddy current loss among the electromagnetic field loss of the magnetic gear is pointed out as the biggest problem in the high speed drive. Among other losses, iron...
A HTS linear synchronous motor (LSM) that uses YBCO-coated conductor as the secondary excitation system and double layer concentrated windings as the primary was recently demonstrated in our laboratory. Two YBCO-coated conductor racetrack coils were wound on a fiberglass frame via the epoxy impregnation technique and injected dc currents to provide a high stationary magnetic field for LSM....
Recently non-insulation (NI) HTS coils using coated conductors (CCs) draw extensive attention because of their self-protecting capability. Closed-loop coils are also promising in the application of electrodynamic-suspension (EDS) Maglev train with superconducting magnets since the heat load of the on-board magnet can be significantly reduced, typically >50%. Therefore, closed-loop NI-HTS coils...
Recently, we investigated High Temperature Superconductor (HTS)-ElectroMagnet (EM) interaction characteristics with experiments and computer simulations. In this investigation, new type of EMs with different geometries were designed and built for comparative analysis. We also set up a three dimensional force measurement system to evaluate the levitation and guidance forces with different EM...
In this paper we present a quadratic approximation method for the limit value of magnetic stiffness in a high temperature superconducting levitation system. The levitation configuration discussed is that of a cylindrical permanent magnet (PM) placed above a coaxial high temperature superconductor (HTS). The magnetic levitation force between the PM and the HTS is obtained on the basis of Kim’s...
A new type of electromagnetic guideway for high temperature superconducting maglev was proposed in this paper. The guideway unit is a fan shaped electromagnet that can generate magnetic field for providing enough levitation and guidance forces. A simple multi-object optimization method was used in order to determine the relative optimal geometrical parameters, so that the electromagnet can...
Superconducting permanent magnet such as bulk, stack tapes and ring-shape magnet has been proved to be a potential candidate for superconducting motors. In real applications, especially the superconducting electrodynamic-suspension(EDS) levitation system, vibrations in all directions during high speed operation are unavoidable. This paper focuses on the demagnetization process of...
The “Divertor Tokamak Test” is an experimental machine currently under construction in Italy, at the Frascati research center of ENEA. The main goal of this project is to explore various divertor solutions for defining the best way to manage power and particles exhaust, in view of the realization of the EU-DEMO machine. The DTT magnet system is fully superconducting and it is based on NbTi and...
ReBCO-CORC wires, long dreamed about practical high current density thin conductors, are now reality and feature diameters in the 2 to 4 mm range. They are multi-purpose, but at CERN specifically developed for application in high-field magnets. CERN is interested to further aid the development of such conductors for possible implementation in the next generation of accelerator magnets and...
Superconducting Nb3Sn accelerator magnet technology start to reach maturity and the 11 T dipole magnets based on that technology are prepared to be installed in the LHC. Performing detailed diagnostics on Nb3Sn model magnets has been vital for giving feedback on the design and fabrication of the magnets and for the conductor performance in that particular configuration. In the last few years,...
Advanced Conductor Technologies has been developing high-temperature superconducting Conductor on Round Core (CORC®) cables and wires wound from ReBa2Cu3O7-x coated conductors for use in high-field magnets. Initial development is aimed at CORC® cable performance goals of operating currents exceeding 5-10 kA and engineering current...
Fluctuation of critical current along the length of conductor is commonly observed in the 2nd generation of high-temperature superconductor tapes. In difference to low-temperature wires it seems that an elimination of this adverse feature is not a simple task. Then it would be sensible to incorporate its description in the standard tape characterization. We report on our effort to develop the...
The “Divertor Tokamak Test” is an experimental machine currently under construction in Italy, at the Frascati research center of ENEA. The main goal of this project is to explore various divertor solutions for defining the best way to manage power and particles exhaust, in view of the realization of the EU-DEMO machine. The DTT machine is relatively compact, and the magnet system works at high...
A pancake coil was prepared with a length of 15-strand ReBCO 2G Roebel cable and studied in detail at different operating temperatures between 4.2K and 77K, cooled with either liquid cryogens or flowing liquid helium gas. The coil was impregnated with epoxy and the transient cooling was predominantly by conduction from current contacts. Critical current measurements were carried out with a...
The use of silicon carbide varistors for quench protection of superconducting magnets has previously been reported [1], where the varistor unit is external to the magnet in a room temperature environment. Here it has been demonstrated that, in comparison to similar linear resistors, the varistor has beneficial effects in both limiting the magnitude of clamping voltages as well as limiting the...
Research and engineering design work of superconducting magnet system of CFETR (China Fusion Engineering Test Reactor) is in progress and supported by China government. The major radius and minor radius of CFETR is designed as 7.2 m and 2.2 m, respectively.
For one hands, such big size will bring big challenges to the magnet system because it will be difficult to get high enough volt...
The National High Magnetic Field Laboratory (NHMFL) is in the fortunate situation to put substantial effort into advancing all three high field magnet relevant types of high temperature superconductor (HTS) technologies, REBCO, Bi-2223, and Bi-2212, as a part of its commitment to develop all-superconducting high field magnets. Here we are presenting our work on Bi-2212 coil technology, which...
Winding REBCO conductors on round cores (CORC) has innovatively transformed REBCO thin tapes to round cables which allow high temperature superconductor to meet low-inductance requirement and offer symmetrical electromagnetic and mechanical properties for large-scale high field accelerator magnets. HTS conductors, however, are known for slow quench propagation and large minimum quench energy,...
Design of CFETR TF Prototype Coil
Wu Yu, Shi Yi, Lu kun, Liu Xiaogang, Qin jinggang, Liu Xufeng, Hao Qiangwang, Li Junjun, Hu Yanlan, Xiao Yezhen, Shen Guang, Han Houxiang, Wei Jin, Fang Chao, Yin Dapeng, Li Jiangang.
Abstract
China Fusion Engineering Test Reactor （hereinafter referred to as “CFETR”）, based on ITER technology and bridged between ITER and DEMO, has been supported by China...
Two subscale coils of Bi-2212 wire have been made and tested in a DOE STTR collaboration between Cryomagnetics and the Applied Superconductivity Center at Florida State University. The coils are used to test the feasibility of using small-diameter wire in a solenoid configuration where single strand wire performance is crucial. If successful, the implementation of small-diameter wire into high...
Hybrid electric aircraft requires high power density for power transmission, which makes the ReBCO conductor-on-round-core (CORC) cable a powerful candidate for the transmission line used in the hybrid-electric aircraft. However, quenching remains one of the biggest challenges in the development of CORC cable, for it can significantly influence the thermal stability and safety of the CORC...
In DEMO fusion reactor the confinement of the plasma is achieved through the magnetic field generated by superconducting coils. The DEMO magnet system includes 16 Toroidal Field (TF) coils, 6 Poloidal Field (PF) coils and 5 modules for the Central Solenoid (CS) magnet. For the TF coils, four winding pack options are presented: one solution reproduces the ITER concept with radial plates,...
Numerous high current conductor designs based on High Temperature Superconducting (HTS) materials for fusion magnets have been recently proposed worldwide.
One of the most promising is the Twisted-Slotted-Core Cable-in-Conduit-Conductor comprised of an aluminum core with twisted slots in which REBCO tapes are stacked and with an external metal jacket. The coolant flows in a central hole and...
Stacks of high temperature superconducting (HTS) tapes magnetized by pulsed fields have been demonstrated a way for the development of the HTS magnet capable of trapping high field. A novel structure of the flux pump was proposed to magnetize the HTS magnet stacks of RE (RE= rare earth) Ba-Cu-O annular plates in this paper. Prototypes of the flux pump constructed of two types of the solenoidal...
We have shown that a persistent current can be induced in HTS coils with the form of double pancakes or single solenoids by the technique of joint-less winding with 2G REBCO tapes. However, the inevitable gap located at the center of the joint-less coil caused very poor magnetic field homogeneity, which was shown by the magnetic field mapping from the previous experimental work. In this paper,...
The critical current degradation of YBCO coils have been observed in a large number of experiments, which have been explained that the thermal expansion mismatch between the YBCO tapes and resins lead to damage of the conductor. The no-insulation coil can avoid the performance degradation, but it has a poorer mechanical strength without any reinforcement. A new impregnation method by ice was...
The 25 T all superconducting magnet designed as a combination of 14 T low temperature superconductor (LTS) background field magnet and 11 T YBCO insert coil has been developed at Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). The electromechanical properties of YBCO coated conductors and magnetic field intensity and orientation dependence of the critical current were...
The advent of REBCO tape has led to the development of tape-wound coils by a number of organizations. The 32 T magnet at the NHMFL uses two coils made of double-pancakes of REBCO installed within five LTS coils. It reached full field in December 2017. This is the highest field produced by an all-superconducting magnet to date. Since the 1970s it has been known that screening currents exist in...
In this article, we presented a design and experimental results of a Bi2223 superconducting magnet cooling by a free-piston stirling cryocooler. Depending on mechanics, thermal and electromagnetic multi-field couple analyzes results, we winding the coils with the type pancake type. We optimized the magnetic field by iron flange at the end of coils to avoid the vertical field effect of the...
Compared to low temperature superconducting materials (LTS), Bi-2212 is more promising due to excellent current-carrying capability in ultrahigh magnetic field. In order to verify the long-line performance and small-scale superconducting magnet technology, a 2 T Wind & React Bi-2212 solenoid insert coil has been designed and fabricated at Institute of Plasma Physics, Chinese Academy of Science...
High temperature superconductor Bi2Sr2CaCu2O8+δ (Bi-2212) exhibits high irreversibility field Hc2 of nearly 100 T, and high critical current density under high field with the Jc of over 6800 Amm-2 under 4.2 K, 15 T. Therefore, it shows great potential in the fabrication of low temperature, high field magnet. In our institute, Bi-2212 multifilamentary round wires with length over 200 m have been...
Screening currents (SC) induced by varying magnetic fields may not only affect the field quality but also cause overstressing of REBCO coated conductor coils, making it a critical issue for NMR and other high-field magnets. We present in this paper results of an experimental and analytical study, performed with small REBCO pancake coils, on SC-overstressing of REBCO coil. Because SC is...
As a novel structure of second-generation high-temperature superconducting (2G HTS) tapes, narrow-stacked HTS wire with 1 mm width was proposed to reduce AC loss. Its fabricated processes are to cut the HTS tapes into 1 mm wide ones mechanically and stack them into one wire through the soldering furnace. In our previous work, compared with the traditional 5 mm wide HTS conductor, the...
The HTS windings in magnets can provide large current excitation in a limited space. However, under high level excitation condition, especially in the case of fast adjusting process, AC loss will occur and lead to reduction of thermal stability. The H-formulation method is widely used and basically meets the requirements of AC loss calculation for thousand-turns coil group. However, for...
CORC is one of the candidates for high magnetic field and large currents. We are interested in applying CORC to HTS power transformers that require not only large currents but also very low AC losses. We measured and calculated the magnetization losses of short straight CORC samples made of striated YBCO CC. The effect of the striation is certain for reducing the magnetization loss, but the...
Dynamic resistance refers to the emergence of a DC electrical resistance in a superconductor carrying a DC transport current that is exposed to an oscillating AC magnetic field1,2. This phenomenon arises due to the interaction between the transport current and moving fluxons in the superconductor. Quantitatively predicting the magnitude of this effect is important when designing and utilising...
AC loss is an unavoidable problem for a conduction-cooled HTS SMES magnet during dynamic operation, which may cause a temperature raise and affect the reliable operation of the magnet. In this paper, the 3D-model calculation method of 10MJ- annular magnet is analyzed. And then, the “Dimensionality Reduction-Inversion” method based on H-equation and homogenization modeling method is proposed,...
Our research group have proposed the introduction of transposed parallel conductors which are generally used in conventional electric power machines and devices in order to realize a large current capacity, uniform current sharing and low AC loss. In previous studies, the additional AC loss due to the formation of the parallel conductors composed of two REBa2Cu3Oy (REBCO) superconducting tapes...
AC loss is an intractable and inevitable issue on high temperature superconducting (HTS) coils and magnets. The HTS coils used in HTS applications will suffer from distorted currents when operate in malfunction. Based on this, AC loss of the double-layer racetrack coil (DRC) carrying harmonic contents in phase or out of phase has been measured with laminated silicon steel sheets (SSS) or not....
We will describe the first persistent-mode medium magnetic field (400 MHz, 9.39 T) NMR magnet which uses superconducting joints between high-temperature superconductors (HTSs). As an ultimate goal, we aim to develop a high-resolution 1.3 GHz (30.5 T) NMR magnet operated in the persistent-mode [1]. The 1.3 GHz NMR magnet requires superconducting joints between HTSs and those between an HTS and...
High magnetic field uniformity is important for various applications, including NMR, MRI and quantum computing. A novel scheme has been developed to significantly improve magnetic field uniformity in a good field region, defined by (Bmax-Bmin)/Bmin, to levels well below 1X10-6 limit achievable in modern NMR and MRI magnets with shimming. This novel scheme can achieve theoretical field...
A portable nuclear magnetic resonance (NMR) superconducting magnet with conduction-cooled cryostat system was under development with central field strength 7 T. The designed diameter of spherical volume (DSV) of the magnet is 0.05 m and the peak-peak homogeneity is 8 ppm. After shimming, the field homogeneity will be improved to 0.1 ppm over a DSV 0.01 m. The magnet is actively-shielded with a...
In this paper, we propose a new concept of “multi-bore” NMR (nuclear magnetic resonance) magnet, where multiple high temperature superconductor (HTS) NNR magnets are closely positioned to form a magnet array. A key benefit of the multi-bore NMR system over its single-bore counterpart may be that it shares some common parts, especially cryogenic system and current lead, thus the overall...
In this paper, a new design method using a stacked multilayer ferromagnetic shim is proposed and experimentally verified. Because of large harmonic errors caused by the screening-current induced magnetic field (SCF) and absence of superconducting active shim coils, ferromagnetic shimming is one of the most important technologies to develop the homogeneous high temperature superconducting (HTS)...
In the ultra-high field NMR (nuclear magnetic resonance) and MRI (magnetic resonance imaging) application with using high-temperature superconducting (HTS) materials, the elaborate analysis of multiple coaxial solenoid coils is essential for the magnet design. The inductance and force were calculated by some authors using analytical and semi-analytical expressions based on double integrations...
A joint method for enlarging the length of a superconducting coil should be developed in order to cope with the power demand of industrial society. There are many kinds of joint methods are proposed to enlarge the length of a superconducting coil with high electrical reliability. Among them, a stop joint box method is known as the most promising method to enlarge the length of a...
With the rise of power level of high power device like magnetic power supply systems of fusion device, the section size of smoothing and current-limiting reactor becomes larger and larger. To keep the linearity of inductance, the structure of air-core with vacuum pressure impregnation (VPI) casting is widely used. In this paper, a numerical method based on equivalent model is adopted to study...
Two types of new organic resins are under development at KEK for the magnet insulation materials. One is Cynate ester resins which will be used in warm magnet insulation instead of usual epoxy resins. One of its typical (possible) characteristics is its radiation hardness. We have already developed a new type of the insulation resin based on Bismaleimide-Triazine （BT) resin. BT resin was...
The insulation system is a key component of Nb3Sn superconducting accelerator magnets under construction for the LHC High Luminosity upgrade (HL-LHC). It needs to ensure the magnet operation at 1.9 K and to guarantee the functionality during the complete service life of the magnet in the accelerator under high mechanical stress and irradiation dose up to 35 MGy. A first set of experimental...
A study on the cryogenic dielectric characteristics for developing a high voltage superconducting magnet system such as a superconducting fault current limiter, a superconducting transformer, and a superconducting cable has been performed. A high voltage superconducting magnet system uses liquid nitrogen as an insulating medium as well as a cooling medium by immersing a superconducting magnet...
The construction of high-performing magnets has to take into account the mechanical properties of the employed materials, and insulation adhesion to the conductor is one of the key factors. ICAS, the Italian Consortium for Applied Superconductivity, after an R&D phase, set up a new production line to process copper conductors in order to prepare, apply and cure a cyanate ester based primer,...
Abstract-High-temperature superconductors motors driven by power electronics or its startup requires an insulation system which prevents pulse voltage in Liquid Nitrogen.Materials like polyimide(PI) or fiber reinforced plastic materials are usually used in insulation system because of its high performance.Due to driven by power electrics,repetitive square wave voltage(RSWV) will be more...
PITHIA is an advanced simulation tool, in-house developed by FEAC Engineering P.C., with currently three available modules for electromagnetic, cathodic protection and fluid-structure interaction problems (either 2D or 3D), which can effectively treat large-scale problems as well. This paper describes PITHIA’s electromagnetic module, focusing on applications such as superconducting accelerator...
Several investigations have shown that ReBCO coils wound without turn-to-turn insulation are self-quench protecting due to the current bypass through layers. However, some of the obstacles that this type of magnets face are charging and discharging delays, directly related to the generation of eddy currents increased by the low contact resistance between turns. The inter-tape contact...
Electrical equipment is tending to miniaturization and high frequency in modern industry development. High frequency transformer (HFT) has a broad application prospects whose volume obeys the law of inverse-squares of the operating frequency. Magnetic properties of its core materials under actual conditions need to be studied.
The soft magnetic ferrites, amorphous and nanocrystalline alloys...
The superconducting magnetic bearing (SMB) has great application potential in flywheel energy storage system (FESS), because of the merits of wear-free, low-drag torque, self-stable, unlubricated and vacuum-compatible operation. A fully high-Tc superconducting (HTS) FESS with a 300 kW power has been established in Japan, 2015. The next generation MW-class FESS needs a larger weight and...
Toroidal magnets are widely exploited in industry and scientific research, involving a vast spectrum of applications, such as thermonuclear fusion, particle detectors, SMES systems and medical devices. Toroidal configurations may involve different number of coils of different planar and three-dimensional geometries; to properly analyse these systems, it is crucial to determine the magnetic...
High temperature superconducting (HTS) materials are nowadays considered as possible candidates for high field magnets, e.g. for fusion and high-energy physics, and for AC or DC power applications. The development of HTS conductors requires extensive information about the impact of the main characteristics of the cable architecture on the electrical performances of the superconducting tapes or...
Recently, there have been a number of studies using empirical machine learning approaches to extract useful insights on the structure-property relationships of superconductor material. Especially, these approaches are bringing extreme benefits when superconductivity data often come from costly and arduously experimental work. However, this assessment cannot be based solely on an open “black...
Transcranial magnetic stimulation(TMS), as a new medical technology with great development prospect, has been shown to be effective in treating a variety of mental illnesses. The stimulation intensity and focality of the transcranial magnetic coil are often used to measure its biological effects. In order to improve its performance, a magnetic core can be added to the existing coil to enhance...
A 9 T NbTi superconducting magnet with large bore is designed and will be fabricated for EMPS (Electro-Magnetic Property measurement System) whose sample space is 50 mm in diameter. To satisfy the large sample space of the system, winding bore of the magnet should be larger than 100 mm in diameter. Since the winding diameter is larger than that of conventional 9 T class NbTi superconducting...
ENEA is currently working on the design of an experimental fusion reactor named DTT (Divertor Test Tokamak).
DTT magnetic system will be realized using superconductor materials thus implying the need for specific protection strategies. In particular, in case of magnet quench, detection and protection devices are needed and they represent a significant cost. The design of quench protection...
In order to protect superconducting magnets, quenches must be detected on time. Unfortunately, conventional simulation predictions are not accurate enough, because they often overestimate the quench detection thresholds. These false triggers lead to frequent and unneccessary shutdowns, which considerably reduce the availability of the entire system and become even more critical for the newly...
Quench detection of high-temperature superconducting (HTS) magnet is carried out using various signals like voltage, current and temperate from the magnet. Normally, the detection point is set to a fixed value, and when the measured value exceeded detection point, it is detected as a quench. The problem of this method is that the detection system may malfunction in a sequence that the user has...
This paper presents a summary of protection studies being performed within the scope of the High-Luminosity Large Hadron Collider (HL-LHC) upgrade with the STEAM (Simulation of Transient Effects in Accelerator Magnets) simulation framework.
The HL-LHC upgrade features new technologies that are to be introduced into the Large Hadron Collider (LHC). This includes challenging Nb3Sn-based...
Quench protection system aims to protect superconducting magnets in Large Superconducting Fusion Device (LSFD) from long time and severe conducting current. A 100kA super-high pulse current with very short pulse width produced by LC commutation circuit, flows reversely into the Vacuum Circuit Breaker (VCB) to force the magnets current cross zero, which ensures the reliable turn-off of VCB to...
The International Thermonuclear Experimental Reactor (ITER) is an international project aimed to build a fusion reactor using a magnetic confinement (Tokamak) for the high-energy plasma. This magnetic confinement it created by a set of various very large superconducting coils, mainly round poloidal field (PF) coils (upto 24 m wide) and D-shaped toroidal field (TF) coils (as high as 16m). The...
The International Tokamak Experimental Reactor relies in magnetic confinement of hot plasma. The main driver for the confinement is played by the Toroidal Field Coils (TFC). These magnets are composed by a winding pack, made of Nb3Sn superconductors, and a surrounding stainless steel structure or coil case (TFCC) which is closed by welding once the WP is inserted in the TFCC. The closure GTAW...
The ITER magnetic system includes the Toroidal Field (TF) Coils. To cope with the fatigue exercised on the TF Coils, and with the deformation resulting from the powerful magnetic fields, 3 Pre-Compression Rings (PCRs) will be placed on top of them and 3 below them. An extra set of 3 will be manufactured as spare and installed below the ITER machine in case there is a need in the future to...
The Pre Compression Ring (PCR) system is a key component of ITER magnetic system that radially constraints the Toroidal Field (TF) coils against the out of plane magnetic forces. Due to its peculiar characteristics (one of a kind component, unidirectional S2 fiberglass in epoxy matrix) an experimental campaign has been planned on both reduced and full scale specimens. The tests purpose is...
The electrical performance degradation of Nb3Sn cables in the Cable-in-Conduit Conductors design has been well documented in literature. The Nb3Sn composite strands exhibit a critical current density that strongly depends on the strain state of the superconducting filaments. During the machine operation, the conductors are submitted to several electromagnetic and thermal cycles affecting the...
Modelling by analytical approach the coupling losses of CICCs used in tokamaks remains a challenge to be reliable at all frequencies. This is usually done using either CPU consuming numerical approaches or heuristic models such as MPAS now used for ITER.
A recently developed analytical model COLISEUM (COupling Losses analytIcal Staged cablEs Unified Model) applies at various scales going...
The cryogenic circuit used to cool a large superconducting magnet such as a tokamak system must be designed while considering the cooling conductance due to the many branches.The KSTAR PF1~2 upper and low magnet have ten and eight cooling channels parallel respectively. The pressure drop of the magnets is adjusted by cryogenic valve and is maintained by a supercritical helium circulator. The...
Typical tokamak fusion device uses CS (Central Solenoid) coil to initiate plasma heating by ramping up the coil with steadily increasing current which induces the plasma inside the vacuum vessel. For the case of the KSTAR (Korea Superconducting Tokamak Advanced Research) which uses superconductor for all of its magnets, this operation brings various AC losses to the magnets including...
Conceptual design of the K-DEMO magnet system has been under way. From the up-to-date design activities, the TF magnets use two different types of cable-in-conduit conductors (CICCs) where high field region uses quite an amount of superconducting wires, but in relatively low field region, substantial amount of superconducting wires should be replaced by copper wires. The stored magnetic energy...
China Fusion Engineering Test Reactor (CFETR) is the next device in the roadmap for the realization of fusion energy in China, which aims to bridge the gaps between the fusion experimental reactor ITER and the demonstration reactor (DEMO). CFETR will be operated in two phases: Steady-state operation and self-sufficiency will be the two key issues for Phase I with a modest fusion power of up to...
The KSTAR magnet system has stably operated since the first plasma in 2008. Scientifically important results have been achieved such as long-pulse plasma operation up to approximately 80 seconds, ion temperature more than 100 million degrees, the world-longest ELM suppression, and so on. During more than 20,000 shots, the CS magnet has experienced temperature rise especially due to AC losses...
The pressure drop in Cable-in-Conduit Conductors cooled by a flow of liquid or supercritical helium is one of the key parameters for the design of the large superconducting magnet systems, which determines the heat removal capability and the thermal stability. In this paper, a new model for predicting pressure drop in Cable-in-Conduit conductors is derived based on an analogy between the...
To perform fast beam switching during spot scanning procedure, the kicker system is adopted in HUST-PTF (Huazhong University of Science and Technology Proton Therapy Facility). The rise and fall time is about 100us, and the maximum repetition rate is 250Hz. A high dynamic performance power supply is required to implement the kicker function. Utmost care should be taken to avoid...
A superconducting multi-coil magnet system has been designed, analyzed and optimized, serving as demonstrator for a high filed Magnetic Resonance Imaging (MRI). The designed superconducting magnet inductance is 3500H. The operating current is 230A. The stored energy is as high as 93MJ. The superconducting material is NiTi/Cu. The normal excitation and demagnetization are completed by the power...
The pulsed magnets power supplies systems to affect injection and extraction of the electron beam have been realized for the Taiwan Photon Source (TPS) and Taiwan Light Source (TLS). The control systems of these pulsed magnets power supplies have been achieved as the well operation interfaces. To accomplish higher reliability operation, the advanced real-time diagnostic toolkit of pulsed...
High-Tc superconducting (HTS) dynamos are simple devices that provide an effective alternative to current leads for driving DC currents in superconducting coils. The simple geometry of these devices consists of some arrangement of superconducting stators and exciter magnets. With recent advances in our ability to model such systems, we investigate the relationship between width of the...
HTS flux pump is a contactless charging method for a superconducting magnet, which can reduce the cryogenic losses associated with current leads. Rotating type flux pump is a simple and practical flux pump, which has great application in charging HTS magnets. For the rotating flux pump, the design of rotor has great impact on the performance of flux pump. In this study, we will change the...
Flux pumps are capable of injecting flux into an HTS circuit without electrical contact. They are ideal alternatives to traditional current sources and current leads to power HTS magnets. These devices make it possible for HTS magnets to be smaller, lighter, and more accessible.
In recent years, our group in Cambridge has developed a transformer-rectifier HTS flux pump switched by...
Recent progress in material science has proved that high temperature superconductors have a great potential to trap significant magnetic flux due to the characteristics of flux pinning, which makes them particularly attractive for a variety of engineering applications. However, using traditional methods to magnetise a superconductor, the applied field needs to be at least as high as the...
Recently, several high temperature superconductor (HTS) companies, such as SuperPower, SuperOx, Shanghai Superconductor Technology (SST), and THEVA, succeeded in improving current-carrying performance of their REBCO products under high magnetic field at low temperature. However, except HTS coils made of SuperPower REBCO tape, there are insufficient reports regarding thermal, electrical and...
As a novel high-temperature superconducting (HTS) conductor structure composed of the stacked 1-mm wide REBCO tapes, Narrow-Staked (NS) wire has been demonstrated to have a significant reduction effect of AC loss and screening current induced field (SCIF) in the insulated HTS coils. Thus, NS wire is a promising HTS conductor design for the practical magnet applications. Meanwhile, due to the...
Abstract:
Comparing with conventional insulated high temperature superconducting (HTS) coil, the no-insulation (NI) one has advantages of high stability, self-protection and fast quench recovery. However, the unstable and non-uniform magnetic field appear in NI coil during exciting owing to too low transverse resistivity among turns. This paper proposed a method for increasing stability and...
When high temperature superconducting (HTS) devices run in the power system, the superconducting tapes may quench due to power system fault. Therefore, quench characteristic is one of the most important characteristics of superconducting tapes. In this paper, in order to obtain the quench characteristics of YBCO coated conductor, we have established an over-current experiment system based on...
NI (no-insulation) winding method have been widely used to develop high field superconducting magnets using REBCO wires due to excellent mechanical and electromagnetic stability. When REBCO magnets are operated in a bath of cryogens such as liquid helium and liquid nitrogen, sufficient cooling is achieved by pool boiling of the cryogen. However, conduction-cooled REBCO magnets must ensure...
We have been studied the no-insulation (NI) technique and co-winding method with various metallic tapes. The improved thermal stability of NI test coils by bypassing the transport current into the transverse direction was experimentally confirmed and reported. However, there are the problems of the transient stability and the reduction of critical current of NI HTS coils due to the thermal and...
The no-insulation coil is expected as a technology that can realize both high current density and high thermal stability which are originally trade-off relationship in REBCO coil application. And this technique has been mainly studied for application to small diameter inner coil of NMR magnet exceeding 30T. In this case, the coil is cooled by 4.2 K liquid helium. On the other hand, we have...
We have tested an intermediate-size HTS stainless steel double pancake coil (132 turns per coil) and discovered dynamic effects during sudden discharge on millisecond scale. Two main approaches have been compared: soft and hard breaks. The soft break is when the power supply is turned off suddenly but the shunt resistors (168 milliohm) is still connected. The hard break uses a high voltage...
Brushless dc motor (BLDC) has high output and high efficiency characteristics. It is possible to reduce the size and weight of the device and is used throughout the society. Among them, vibration and noise reduction are becoming important issues as they are used in household appliances and automobiles adjacent to people.Vibration and noise are caused by electrical causes such as spatial...
Currently, the ISG is commercialized and under active research in the 48V hybrid system. However, in a typical vehicle using a 12V system, the starter motor and generator are operated separately. In this paper, we report the development of a general advanced integrated starter-generator(AISG) for vehicles using 12V power supplies. The specifications of the power source are lower than that of...
1) Introduction
Brushless DC motor (BLDC) have wide operating range and can high power density and high torque. Therefore, BLDC is used in various fields such as vehicle, aviation, home appliances. However, there is a problem that a torque ripple occurs in a phase commutation section in which a current flows. In order to overcome such problems, various studies have been conducted to improve...
Flux-modulated permanent magnet (FMPM) motors have attracted widespread attention in many applications due to the superiority of low-speed large-torque, such as the electric vehicles. In the type of motors, the flux modulation effect is the key to obtain the excellent torque performances, which realize the electric gear operation by forming the matching between the magnetic fields with high PM...
Flux-modulated permanent magnet (FMPM) motors have attracted considerable attention due to the predominant torque performance in low speed condition. Recently, the flux modulation principle is always to be developed in diverse PM motors. Intensive study results demonstrate that the harmonics in motor airgap are abundant, and they are essentially the deliverer during the process of the motor...
Brushless direct current (BLDC) motors have the advantage of power density and low maintenance cost compared to DC motors. DC motors are increasingly being replaced with BLDC motors due to low cost of driving devices and the development of control technology. In particular, outer rotor type BLDC motors have higher power density than inner rotor type BLDC motors since permanent magnets (PMs)...
A bearingless permanent magnet slice motor(BPMSM) has compact structure and high efficiency, which can realize the rotor magnetic suspension at five degrees of freedom. Bearingless pumps have been established in applications that demand high temperature and corrosion. The extreme environment, especially the high temperature environment, will cause the PM demagnetization fault and so on. As one...
A novel axial-radial flux permanent magnet machine (ARFPMM) is proposed to improve the performance of PM machine. The ARFPMM is capable to reach higher torque density and lower cogging torque than traditional axial and radial PM machine when designed properly. To reach higher performance, T-type SMC core, reluctance rotor, and PM rotor are applied. The T-type stator core is made of soft...
The vibration occurring in an electric motor can be largely divided into mechanical vibration due to nonaligned bearings and shafts, and electromagnetic vibration by the electromagnetic force. For existing industrial electric motors, the mechanical vibration associated with the life of the motor was the most important concern. However, in recent years, electric motors—such as the ones used for...
Spoke type Permanent magnet synchronous motors (PMSM), which are superior to other PMSM in terms of output density by maximizing the surface area of permanent magnet (PM), have recently been actively studied. However, spoke type PMSM are magnetically separated by connecting each pole of the rotor core to a magnetically saturated rib or bridge. Therefore, there is a rotor structure in which...
Nowadays, hybrid electric vehicles (HEVs) have been employed and developed extensively for promoting the rapid development of resource-conserving and environment-friendly society. Due to the multi-mode operations of the HEVs, the high integrated electric drive system with the motors which features the high torque density, high efficiency, and wide speed range are becoming the main trend in the...
This study shows the novel rotor shape of the spoke-type PMSM for a washing machine to improve power and widen operating range by changes of inductance in the rotor and air gap. Applying a new shape to the rotor results in an inductance change in some areas of the rotor in which low magnetic flux density existing, which in turn changes the magnetoresistance in the air gap. As the inductance...
Our group has been conducting various studies of high-temperature superconducting induction/synchronous motor (HTS-ISM) for next generation transportation equipment. The HTS-ISM has various advantages, such as co-existence of synchronous and slip rotation modes, high efficiency for variable speed control, high torque density. For the HTS-ISM with copper stator winding, the torque density and...
Due to the high thrust density and operational speed, superconducting linear synchronous motor is considered a favorable propulsion system for high-speed ground transportation. Korea Railroad Research Institute (KRRI) has researched on high-Tc superconducting linear synchronous motor (HTS LSM) to develop new high-speed transportation of which speed is over 500 km/h. As a feasibility study for...
Axial flux permanent magnet machines (AFPM) are being increasingly used in a great of industrial applications e.g. the electrical vehicle and wind generators, due to its very compact structure and high torque density. The single stator and single rotor configuration is the basic structure of axial flux machine. For AFPM the fractional slot concentrated winding and surface mounted PM structure...
Superconducting tape-based stacks used as trapped magnetic flux magnets in electrical machines are subject to an AC-demagnetizing field. This study provides analysis of trapped flux and demagnetization of several stacks’ architectures for electrical machines applications. This work is an application-driven enhancement of a previous study on stacks architecture in regards of trapped flux...
Flux reversal permanent magnet machine (FRPMM) is a special kind of permanent magnet machine with the permanent magnet (PM) installed on the stator side and there is no winding or PMs on the rotor side. Claw pole machine (CPM) is a special kind of transverse flux machine (TFM), with the adopted claw pole teeth, the torque ability and power factor of CPM can be even higher than those of TFM....
The objective of this paper is an analysis method for traction motor which targeting to electric bus and trailer. The type of the studied motor is IPMSM(Interior Permanent Magnet synchronous motor) which has delta type magnet topology of the rotor. It is possible to maximize reluctance torque and output characteristics by arranging the permanent magnet arrangement of the rotor in delta...
Low-speed and high-torque permanent magnet motors (LSHT-PMM) are widely used in many industrial fields. Due to the inherent characteristics, the outer diameter of the LSHT-PMM is large. Therefore, in order to make full use of the internal space of the motor, a double stator structure is proposed in this paper. In order to reduce the amount of permanent magnets (PMs) and reduce the cost, a PM...
Our group has been developing a High Temperature Superconducting Induction/Synchronous Motor (HTS-ISM) for highly efficient transportation equipment. So far, the 20 kW class prototype, which consists of BSCCO rotor and copper stator, has already been developed and shown its excellent characteristics based on experiment and analysis. Furthermore, the 50 kW class model, in which both the rotor...
Transformer is important in power system. No-load loss and apparent power of amorphous alloy transformer core change obviously with temperature. Moreover, the inner temperature varies in large scale. At present, little research has been done on no-load loss of amorphous alloy cores with temperature change. Therefore, it is very important to study the no-load loss at different...
Fully turboelectric propulsion systems with lightweight and high power density are one of the solutions to realize future electric aircrafts. Our research group started to develop 10 MW fully superconducting synchronous generators and 2 MW motors. In this system, we designed so that the generators supply electric power at the voltage of 6.9 kV, however, the motors operate at the low voltage of...
Insulation materials have different electrical characteristics according to temperature and voltage frequency. These characteristics are very significant factors for the insulation design of high voltage power apparatus. Since there are not always consistent overvoltages, it is necessary to ensure the dielectric strength against various overvoltages. In particular, high voltage power...
Residual flux of the power transformer will accelerate the magnetization saturation of transformer core and generate high transient inrush current. Generally, the peak value of inrush current generated by residual flux in the core can reach 6-8 times of the rated current, which endangers the mechanical stability and insulation strength of the power transformer windings and destroys the normal...
Conductor on Round Core (CORC®) cables with scalability, flexibility, strong mechanical strength and high current density are of large potential for different power applications. In this paper, CORC® Cables are proposed to be the secondary winding for superconducting fault current limiting transformer (SFCLT). In order to evaluate the working performance of CORC® cable in SFCLT, firstly, a...
Abstract: Based on the finite element method (FEM), a simulation model of a single-phase HTS transformer was established according to a developed HTS transformer, and the simulation results are in good agreement with the experimental data. On this basis, a 120kVA/6kV single-phase HTS transformer was designed, the primary windings were solenoid coils consisted of 8 helically wound layers, and...
Traction transformers are key components for the Chinese high speed train system, and it is hoped that a superconducting version will replace oil-based conventional transformers in this application. Since 2018 Beijing Jiaotong University has been leading a six partner project, funded by the Chinese Ministry of Science and Technology (MOST), to develop a 6.5 MVA HTS traction transformer. The...
When a large power transformer is switched on, the residual flux in the iron core may cause inrush current, which may cause the transformer to no longer be put into operation, thus affecting the continuity of power supply in the power grid. However, the traditional methods can only estimate the residual flux. It is impossible to effectively weaken the residual flux. Therefore, the study of...
This paper is a the fault current limiting characteristics of superconducting fault current limiter due to three phase ground fault in power system.
In this system, two superconducting elements are connected to a-phase and c-phase respectively, and a transformer type superconducting fault current limiter is proposed to limit the fault current in case of a ground faults.
In order to measure...
The distributed power generation has increased due to the development of the electric power industry and the active generation of renewable energy. This causes a large increase in the fault current when fault occurs, which exceeds the capacity of the existing protective device. Thus it creates a risk of shutdown failure. The superconducting fault current limiter (SFCL) has been demonstrated by...
A Wireless Power Transmission (WPT) system for a railway vehicle has been investigated to reduce the greenhouse gas emissions in a diesel vehicle. However, the WPT system is required to transmit the electric power of several hundred kW in a short time while the railway vehicle is stopping at a station. Since there are power converters and control devices under the floor of the railway vehicle,...
45 T is the highest continuous magnetic field available to the scientific user community, and this now since practically 20 years. We address the question of how to access the next level, defined as 60 T, with a hybrid magnet. The outsert, wound from low-temperature superconductors (LTS) will generate the highest field possible: 18 - 20 T in a 1 m bore. For the inner part, two approaches are...
A design study started in 2014 at CERN for a Future Circular Collider. A new 100 km ring-tunnel for the collider magnets is foreseen as well as new particle detectors to probe electron-positron (ee), electron-hadron (eh) and hadron-hadron collisions (hh). A conceptual design report is due in 2019 for all FCC collider and detector options. Baseline designs for the various Detector magnets were...
The design for a new approach to cable-in-conduit (SuperCIC) for use in the high-field windings of tokamaks. Two layers of high-field superconductor wires are cabled onto a thin-wall perforated center tube. An overwrap is applied and the cable is inserted as a loose fit into a sheath tube. The sheath tube is drawn down onto the cable to compress the wires onto the center tube and immobilize...
A 100 T pulsed magnet of triple coils was developed in WHMFC in 2018, the outer coil was powered by a 100MJ/100MW pulsed generator, and the middle and inner coils are energized by capacitor banks. The inner and middle coils are made of CuNb wire, and copper wire for the outer coil, the outline size of the magnet is 800 mm in O.D. and 1200mm high. The magnet failed at about 83 T during test,...
The magnet system of the Muon to electron (Mu2e) experiment at Fermilab consists of three solenoid magnets: the Production Solenoid (PS), the Transport Solenoid (TS), and the Detector Solenoid (DS). The S-shaped TS contains 52 coils grouped into modules, which are typically 2 coils shrink fitted into Al shells. These modules are further grouped into units made of 1-3 modules. As part of the...
The Dresden High Magnetic Field Laboratory (HLD) is a pulsed-field user facility which provides external and in-house researchers with the possibility to perform a broad range of experiments in pulsed magnetic fields [1]. Being a member of the European Magnetic Field Laboratory (EMFL), HLD receives more than 100 scientific proposals annually.
The Dresden High Magnetic Field Laboratory...
The ALPHA-g experiment at CERN aims to be the first-ever to precisely weigh antimatter under Earth’s gravity, by “dropping” antihydrogen atoms with a magnet system. The anti-atoms are initially confined inside a vertical octupole and between two end cap coils. The currents in the coils are then gradually decreased to release the anti-atoms. The up -down balance of the escapes depends on...
ReBCO-CORC Cable-In-Conduit Conductors are high-current multi-strand conductors aimed for application in large scale magnets, for example in magnets for particle detectors and fusion experiments; but also for use in bus lines feeding high currents to magnets or other devices. ReBCO based conductors open up the operating temperature range of 20 to 50 K, not accessible by any other practical...
Ultra-high field pulsed magnets must simultaneously satisfy a number of often competing electrical, electromagnetic, structural, thermal, and economic constraints. To produce the highest field possible, nondestructive pulsed magnets are designed to operate at the limits of mechanical strength and electrical capacity of conductors. In this presentation, we will introduce a coupled...
The MADMAX (MAgnetized Disc and Mirror AXion) project is a dark matter experiment that aims at finding axion particles with masses in the range of 100 µeV. In order to achieve this goal, the chosen approach is to use a detector comprised of many magnetized dielectric discs put in parallel in front of a mirror. The relevant level of magnetic induction needed to increase the probability of...
Material is a key issue for the high field magnet development. For DC resistive magnets, copper alloys with high strength and high electrical conductivity from room temperature up to 200 °C are required.
Steady high field resistive magnets developed worldwide used mainly two technologies: the Bitter and the polyhelix one. Each technology encounters material limits.
In the case of Bitter,...
Searching for axion like particles is one of the top priorities in particle physics. Using helioscopes is a promising technology to detect solar axions. The conceptual design of the state-of-the-art facility, the International Axion Observatory (IAXO), has resulted in a 22 m-long / 660 MJ stored energy, toroidal magnet system comprising 8 racetrack coils. In order to ensure readiness of the...
The EUROfusion DEMO is being designed as the fusion machine to be built after ITER. During the preconceptual phase, several design options are investigated by theoretical analyses as well as tests on newly developed conductor prototypes.
One design option for the toroidal field magnet (TF) and central solenoid (CS) is based on flat Nb3Sn forced-flow conductors made with react&wind technique....
Copper-based conductive wires with both a high strength and a high electrical conductivity could find applications in aerospace and power engineering as well as in niche scientific applications such as materials for the production of high-field pulsed magnets. Indeed, in order to produce non-destructive fields, the coils must be wound of wires with a very high mechanical strength to resist...
The Precision Experiment on Neutron Lifetime Operating with Proton Extraction (PENeLOPE) will use a large superconducting multipole magnet to trap ultracold neutrons. To achieve this, a large volume of 750$~$L needs to be enclosed within a steep magnetic-field gradient of at least 2$~$T, requiring a unique multipole arrangement with a high current density of 316$~$A/mm$^2$ and thin support...
The engineer design for CFETR, “China Fusion Engineering Test Reactor”, has start since 2017. Its magnet system includes the Toroidal Field (TF), Central Solenoid (CS) and Poloidal Field (PF) coils. The maximum field of TF will get around 14.5 T, which is much higher than that of other reactors. One full-scale TF coil will be built. Tremendous investigations need to be made in the development...
With the faraway goal of a 100 TeV new hadron-hadron collider, the ambition for very high field accelerator magnets has never been so broad. The technology choice between Low Temperature Superconductor (LTS) Nb3Sn and High Temperature Superconductors (HTS) for such a machine remains to be made and might lead to a hybrid solution. In all cases, the challenges are ahead of us: from...
The design of a large purpose built cryogen-free magnet is reviewed. The system has been manufactured for the Fundamental Neutron Physics Beamline at the Spallation Neutron Source in Oak Ridge, Tennessee.
The magnet system will house a custom spectrometer and be used to measure a, the electron-neutrino correlation parameter, and b, the Fierz interference term in neutron beta decay.
The...
Abstract—An 10T superconducting split magnet with a room-temperature bore of 40 mm was designed, manufactured and tested for X-ray diffractometer at The High Magnetic Field Laboratory in Hefei, China. The superconducting split magnet provides room-temperature splitting gap of 10 mm and scanning angle of 160 degrees for X-ray beam. As a result of magnetic field intensity considerations, the...
As a significant research method, quasi-continuous high magnetic field (QCMHF) can meet scientific experimental requirements for higher magnetic intensity, longer flat-top pulsed width and lower ripple in the field of physics, biology and other scientific fields. In this paper, a QCMHF system designed by multi-objective optimization method is present to obtain the magnetic intensity of 70T...
The repeated pulsed high magnetic field system is widely used for neutron diffraction, terahertz radiation, guiding magnetic field and so on. In these applications, more and more attentions are paid on magnetic field waveform consistency. The pulsed generator power supply, with large energy storage and controllable output voltage, is suitable for generating repeated controllable pulsed...
Repetitive pulsed high magnetic field (RPHMF) provides a novel solution for the frontier researches in the areas of condensed matter physics, materials science, biomedicine, and so on. Significant amount of attentions have been paid to the study of RPHMF by researchers. As the higher demand for magnetic field intensity and pulse frequency of RPHMF, the repeated supplement of energy storage and...
As an important extreme experimental condition, high magnetic field plays an irreplaceable role in the frontier scientific research, such as condensed matter physics, new materials processing. The main pulsed high magnetic field laboratories in the world are constantly working to generate higher pulsed magnetic field. A nondestructive magnet aimed at generating very high pulsed magnetic field...
We developed a 600kW pulsed DC power supply employing two pairs of a self-excited induction motor/generator (IMG) and a flywheel for toroidal field coils (TFCs) of Plato. Plato is a new tokamak device to measure plasma turbulence precisely, which is under construction at Kyushu University in Japan. In the presentation, we will describe the details on the structure and experimental results of...
The Deep Underground Neutrino Experiment (DUNE) has formed a near detector design group (NDDG) tasked with delivering a CDR by the end of the year. The DUNE Near Detectors will be housed in an underground hall on the Fermilab site. The two main detector systems are a liquid argon detector and a high-pressure gas time projection chamber (HPgTPC). The HPgTPC requires a magnet that generates a...
The ultimate frontier of the particle physics beyond the Standard Model is the research of axion-like particles, to explain the absence of CP violations in the strong interaction and provide dark matter candidates. In the MADMAX (MAgnetized Disc and Mirror AXion) experiment, the principle of axions detection relies on their predicted emission of an electric field proportional to the square of...
The proposed IDEA Experiment (International Detector for Electron-positron Accelerator) for probing ee+ collisions at the Future Circular Collider FCC is conceptualised around an ultra-thin, radiation transparent 150 MJ superconducting solenoid of 6 m length and 4 m free bore providing a magnetic field of 2 T for the inner tracking detector. Positioning the solenoid around the inner detector,...
The ALPHA experiment at the CERN Antiproton Decelerator facility underwent a major upgrade in 2018. Amongst other improvements, key is the rotation of the atom magnetic trap axis, which is now vertical. Bilfinger Noell designed and fabricated the 2 m long superconducting vertical solenoid, which provides the 1 T background field for the experiment. This is an active shielded, conduction...
This work was performed as part of the international Project 8 collaboration. The goal of the Project 8 experiment is to measure the absolute neutrino mass using tritium beta decays, which involves precisely measuring the energies of the beta-decay electrons in the high-energy tail of the spectrum.
The experimental installation of the Project 8 Atomic Tritium Demonstrator requires a magnet...
The Jefferson Lab 12 GeV Upgrade of Experimental End Station Hall B required a new detector system that would be more sensitive to forward going particles and handle higher luminosity. This new detector is CLAS12 and includes two superconducting iron-free magnets – a torus and a solenoid. The Torus magnet consists of 6-trapezoidal racetrack-type coils while the solenoid is an actively shielded...
Nuclotron-based Ion Collider state-of-art design involves innovative solutions in superconductive applied technology. Thanks to its consolidated experience, ASG has been directly involved into the program by providing to Joint Institute for Nuclear Research (JINR) a large 0.5 T Nb-Ti superconductive magnet (5.8m diameter, 8.1m length) equipped with active (resistive) modulation system. Typical...
The extraction line of the future synchrotron SIS100 will have a series of three normal-conducting magnetic septa which deflect the beam upwards. Underneath the third septum there will be a beam stop for emergency extraction. Therefore, the entire region will be very likely activated with anticipated doses that forbid manual installation of a heating jacket. A mechanism which would...
In high intensity circular accelerators such as Rapid Cycling Synchrotrons (RCS) and Fixed Field Alternating-gradient (FFA) synchrotron, maximum beam intensity is limited by beam loss. Suppression of beam scatterings occurred in beam extraction system, especially in septum magnets, is one of the key issues to achieve low beam loss rate. Application of massless septum may be a promising way...
An electron lens – a novel instrument in accelerator physics to manipulate hadron beams with a magnetically confined electron beam - is under development at GSI, Darmstadt. It will be used to compensate the ion beam’s space charge by an overlapping electron beam and therefore may help to increase the intensity of primary beams in the low energy booster synchrotron SIS18 for FAIR. The main...
The new accelerate facility HIAF is under constructing in IMP (Institute of Modern Physics), Chinese Academy of Sciences. It consists of a linac, a booster of BRing and a spectrometer ring of SRing and some terminals for experiments. The electron cooling technology is applied in the SRing, which is composed of solenoids and racetrack coils. In this paper, the magnetic field of the electron...
Fast kickers such as strip-lines along with lambertson magnet or thin septum magnet could support on-axis injection for Diffraction Limited Storage Ring (DLSR), in which traditional off-axis injection becomes inadequate. This paper focuses on the designing, manufacturing and process optimization of thin septum magnet. The scheme of eddy-current type thin septum magnet (the thinnest portion is...
The design of focusing solenoids used in accelerator magnets or other charged particle beam applications usually has some general design requirements such as focusing strength, stray field, and eddy current losses. In superconducting solenoids specific requirements often include mechanical stress, cryogenic performance, and quench protection. In resistive solenoids specific requirements...
The design of the compression magnet in the magnetic trap type magnetic compression device has an important influence on the compression effect. Due to the large diameter (0.3m) of the vacuum chamber, and the severe eddy current in the metal cylinder induced by the rapidly changing current (700-1100kA/100μs) of the coil, the radial distribution of the magnetic field in the magnetic mirror...
This paper develops and summarizes analytical formulations of radial and tangential stresses of superconducting, no-impregnated solenoids, based on a multilayer model. The analysis takes into account the fabrication steps (pre-winding and reinforcement), cooling-down and energization of the coil (magnetic loading). Both isotropic and orthotropic cases are considered.
Representative...
This paper deals with the mechanical characteristic and strain profile in a 5 T NbTi superconducting split magnet system, which provides a strong background field for the multi-field test facility established in Lanzhou University of China. The design of the split magnets, composed of 14 coils wound with NbTi wires, was adopted to satisfy a large test space (Φ100mm*800mm) for mounting the...
An electromagnetic force has an important effect on the performance of high temperature superconducting magnet. The superconducting magnet can be impregnated with composite resin in order to improve its mechanical stability. A three dimensional model was established by COMOSL finite element analysis software to analyze the electromagnetic stress and strain. The results show that the maximum...
Compressive magnetic radial stress is favored, over tensile one, for a high field magnet, mainly because it lowers the overall peak magnetic stress within the windings of the magnet. It is of particular importance for a no-insulation (NI) high temperature superconductor (HTS) magnet, because the compressive radial stress leads to “good” turn-to-turn contact that is essential for current...
It is well-known that REBaCuO, where RE denotes rare-earth elements, superconducting bulk materials can trap large magnetic field in the compact space. Since REBaCuO bulk materials are subjected to electro-magnetic force, improvements of the mechanical properties of REBaCuO bulk materials are indispensable for the development of high-performance devices. However, conventional REBaCuO bulk...
In designing high field magnets, the enormous mechanical stress on the magnets due to the Lorentz force must be considered. However, the common stress–strain calculations with BJR and/or force balance equation barely considered the frictional force between the superconducting tapes. In this study, the effects of frictional force between these tapes on the stress–strain characteristics were...
REBCO coated conductor (CC) has been applied to high field magnets due to its high critical current density ($Jc$) and high tensile strength. In order to further improve in-field $Jc$, we have developed EuBCO CCs doped BaHfO$_3$ (BHO) as artificial pinning centers (APCs)$^{[1]}$. Since the EuBCO nanocomposite films with the BHO secondary phase is similar to the structure for improving the...
The research and development on the applications of REBCO superconducting coil to the high field magnets for NMR, MRI, accelerator and so on are in progress. In coils wound with REBCO tapes, large screening currents are induced by the radial component of the magnetic field. The magnetic field due to the screening current (hereinafter referred to as screening current-induced field) is generated...
Understanding the human brain in neuro scale is one of the main scientific challenges in the future. The sub-micron Magnetic Resonance Imaging (MRI) is significant to the structural and functional research of the human brain. The important way to improve the resolution of MRI scanner is increasing the magnetic field B_0, as it is well known that the signal to noise ratio (SNR) is proportional...
The Nb3Sn Rutherford cable and composite conductor is developed for 14T Magnetic Resonance Imaging (MRI) magnet project in China. Part of the project is devoted to the Electromagnetic (EM) behaviors studies of the deformed Nb3Sn strands from the cabling process. The magnetization characteristic of deformed Nb3Sn strands by artificial rolling method which simulates the transverse deformation is...
The objective of the magnet design for MRI is first to ensure the field intensity and homogeneity in the central imaging area, and meanwhile to minimize the magnetic leakage of the stray field. Based on this, an optimal design method of 14T actively shielded MRI magnets is proposed in this paper. Firstly the current carrying region of the magnets is subdivided into two-dimensional array grids,...
A 7 T superconducting magnet was designed and under fabrication for animal magnetic resonance imaging (MRI). The magnet includes two primary coils, four compensating coils and three shielding coils. All the coils together produced a homogeneous magnetic field over an imaging sphere with diameter 0.130 m and the stray field was actively-shielded within an area at longitudinal length 3 m and...
We present FEM results of a magnetic design study for 7 T, whole body, actively shielded MRI using Nb3Sn conductor. Nb3Sn strand was used to enable the development of short (1.4 m) segmented coil designs, as opposed to the nearly 2 m long compensated solenoid designs needed for NbTi machines. The use of Nb3Sn strand will allow a conduction cooled design, if quench is properly managed. We...
In superconducting magnetic resonance imaging (MRI) systems, time-varying eddy currents in the conducting cryostat structures are induced by switched gradient coils. These eddy currents increase thermal loads of the cryostat, create acoustic noise, lead to image distortion and limit the application of fast MR sequences. In this paper, a fast coupled circuit network method is employed to...
In magnetic resonance imaging (MRI) system, the magnetic field homogeneity of the imaging area plays a decisive role in the quality of images. Due to assembly errors or the effects of the surrounding ferromagnetic material, the homogeneity fails to meet the design value, which makes the images deformation, and it is necessary to take measures to shim. Passive shimming uses the magnetization of...
The Magnetic Resonance Imaging system（MRI）is an important diagnosis and treatment method of modern medicine. Benefiting from the advancement of superconducting magnet technology, the performance of MRI is continuously improved. In superconducting MRI, the main coils, as the most critical components, greatly determines the quality of images, further affecting the diagnosis. Therefore, the...
In ultra-high field magnetic resonance imaging (MRI) systems, the wavelength of the radiofrequency (RF) field is comparable to the size of imaging object, thus causing complicated coil-tissue interactions, which can lead to detrimental changes of the magnetic field (B1 field) and thermal intensity in human tissue. However, the homogeneity of B1 field and safety is critical for the RF coil,...
We have finalized the design of a full-scale tabletop 1.5-T/90-mm MgB2 “finger” MRI magnet system for osteoporosis screening based on our preliminary test results of small coils and superconducting joints. The magnet will operate in persistent mode at 10 K with an additional 5 K temperature margin. The magnet design satisfies the required specification of a field homogeneity of <5...
This paper presents the design, manufacturing and testing of a 2 + 3 T high field MgB2 ø178 bore solenoid magnet demonstrator (around 55 kgs). The magnet was designed to produce 2 T standalone at 10K and to be operated in a homogenous background field of 3 T. The magnet is helium free and is cooled down by a cryocooler. Three lengths of Columbus MgB2 conductors (1.6 kms) were used to wind the...
Recently, we developed a 0.5-T/300 mm MgB2 magnet using the partial insulation (PI) winding technique that only employs layer-to-layer insulations without the turn-to-turn insulations; the magnet was self-protective but has a significant charge–discharge delay. In this study, the use of Cr-coated MgB2 wires was proposed as an alternative solution to enhance the characteristic resistance of the...
The temporal stability of the magnetic field generated by an MRI magnet is of critical importance for higher resolution medical imaging. However, large screening currents are induced in High Temperature Superconducting (HTS) tapes such as REBCO tapes during the excitation, and attenuated after the excitation due to the flux creep of the HTS tapes. The temporal variation of the magnetic field...
A magnet consisting of five no-insulation (NI) double pancakes (DPs) has been constructed and tested. In this paper, operating currents in each excitation mode were optimized to achieve the highest magnetic field and three excitation modes of the magnet have been conducted in 77 K to compare. Test results showed the central magnetic field increased by multiple sources. Charging performance and...
Generally, MgB2 wires possess a niobium diffusion barrier to prevent an unacceptable reaction between magnesium powder and copper stabilizer. However, given that niobium is costly, extensive studies were conducted to replace the niobium diffusion barrier with iron. Nevertheless, the MgB2 wire with iron diffusion barrier is not yet practically applied to magnetic resonance imaging magnets...
Since UHF MRI offer the possibility to study in a deeper way the brain functionality, these kind of magnets are becoming essential in neuroscience research. ASG is involved in this sector with an active shielded, zero boil-off 7T/700 bore magnet. The magnet with stringent dimensional parameters has been designed and developed by ASG superconductors team for Magnex MS Inc., in order to fulfil...
The radioactive dose rate in the area behind the target of the Super-Fragment Separator (Super-FRS) will be so high that most organic materials will be destroyed in a short period of time. After 20 years of operation an accumulated dose of more than 280 MGy is expected at the most critical parts. Special magnets consisting of radiation resistant materials must be used. Three dipoles, three...
The East Area (EA) is a facility for experiments, beam tests and irradiation operated at the CERN Proton Synchrotron since over 55 years. The experimental area requires high availability, which has been increasingly jeopardized due to the age and reduced reliability of the installed components, in particular magnets and power supplies.
The CERN management has then decided to completely...
The CERN PSB (Proton Synchrotron Booster) is currently under-going a major upgrade with an increase in both injection and extraction energy. With the connection of the new LINAC 4, which replaces the now decommissioned LINAC 2, the energy of the beam to be transported to the PSB is increased from 50 MeV to 160 MeV. Simultaneously, the PSB will be upgraded to provide protons to the CERN PS...
Proton beam is an effective means of radiotherapy for tumors. During the transmission of the proton beam from the accelerator to the treatment head, the direction of the beam is usually changed by the magnetic field generated by dipole magnet. A variety of magnets are arranged in a radiotherapy system using a rotating gantry for proton beam transmission. The 90 degree magnet is placed above...
Proton beams have several features that make them very effective in radiation therapy applications. These include high dose localization as well as high biological effect around the Bragg peak. Moreover, magnetic scanning methods allow one to spread an ion beam to an exact image of a complex tumor shape. The ion scanning system usually consists of two magnets, each scanning horizontal and...
Proton therapy is regarded as one of the most advanced radiotherapy methods for its unique Bragg Peak. As a medical apparatus, the proton therapy facility must deliver stable and accurate dose or proton beams to patients. Huazhong University of Science and Technology (HUST) was funded in 2016 to build such a machine, known as HUST-PTF. The HUST-PTF uses a superconducting cyclotron to produce...
Correction magnets with permanent magnets are investigated. They need to generate both polarities of magnetic fields, which can be realized by rotating permanent magnet rods. Such a magnet system will reduce not only electricity but also maintenance cost. The structure and the field adjustment scheme of a trial conceptual design will be discussed.
Strong magnetic fields are demanded for advanced accelerators. As a cost-effective option other than HTS (High Temperature Superconductors), permanent magnets may be applied in the hybrid magnets to generate the strong magnetic field. One of the most promising permanent magnetic materials for the hybrid magnets is praseodymium permanent magnets (PrFeB). Although the remanent field of...
We prepared a series of 2G HTS wires with systematically varying gadolinium content in the GdBCO layer grown by pulsed laser deposition (PLD) and characterized by them by transport Ic measurements over wide ranges of temperature (T) and magnetic field (H). The samples were fabricated using commercial production equipment at SuperOx and contained different concentration of Gd, starting from the...
REBCO coated conductors (CCs) are promising for high field magnets because of their high in-field critical current density (Jc) performance and high tensile tolerance. To further enhance the in-field Jc, doping artificial pinning centers (APCs) such as BaMO3(M : Zr or Hf etc.) into REBCO film is well known technique. We have developed BaHfO3 (BHO) doped EuBCO CCs using a hot-wall type...
The development of second generation high temperature superconductors (HTS) cable with larger current capacity and lower AC loss are very promising for building fast cycled accelerator magnets. In order to enhance the properties of HTS cable under the different physical fields, several HTS cable structure suitable for magnet application have been proposed by twisting, transposition, stacking,...
High Temperature Superconductors (HTS) are currently considered as promising candidates for high current Cable-In-Conduit Conductors (CICC) for large high-field magnets. In many cases, these CICC are formed from several HTS strands which themselves are formed from individual HTS tapes. These stranding concepts often use stacks of tapes or wrapped-tape arrangements.
Large effort is presently...
Abstract —This paper mainly presents an AC loss numerical calculation of the superconducting strand in AC magnetic fields at 4.2K. Quasi-isotropic strands fabricated by second generation wires are stacked to a center symmetric structure. A 2D simulation model of strands was established based on the finite element simulation software Comsol Multiphysics，from which the distribution of magnetic...
High Temperature Superconductor CrossConductor (HTS CroCo) is manufactured by soldering REBCO tapes of two different widths in a cross-shape form. In a new long length fabrication process, the HTS CroCos are already embedded in solder to obtain a round outer shape. This allows to add an outer copper tube around such an HTS CroCo for increased mechanical and electrical stability. The mechanical...
Superconducting Conductor on Round Core (CORC®) cables with scalability, flexibility, strong mechanical strength and high current density have become practical conductors in high-field magnets for fusion machines and particle accelerators. However, when it works in a high background magnetic field, the high mechanical stresses that generated in the CORC® conductor can result in irreversible...
High temperature superconducting tapes are subject to periodic stresses and strains during AC applications, which may cause performance degradation of HTS tapes. In response to this problem, we built a periodic stress fatigue test platform for HTS tapes, and tested the critical current degradation characteristics of YBCO tapes with two different stabilizing layers under periodic stress. The...
The performance degradation of High Temperature Superconducting (HTS) tape, which may be influenced by various heat exchange conditions due to device structure, is of significant for life assessment of HTS devices under repetitive overcurrent. In this paper, considering stabilizing layer materials and heat exchange conditions, a series of repetitive overcurrent experiments were carried on YBCO...
Abstract-- In order to improve the engineering current density of high-temperature superconducting strand, we developed a kind of quasi-isotropic superconducting strand stacked by 2mm wide REBCO tapes. Minumum quench energy (MQE) and quench propagation velocity (QPV) of quasi-isotropic superconducting strands with copper, aluminum and stainless steel sheaths in liquid nitrogen (LN) were ...
A structural model has been developed for the Cable-in-Conduit Conductor (CICC) made with 2G HTS superconductors inserted in a helically slotted aluminum core (concept proposed by the ENEA Superconductivity laboratory [1]). The cable is particularly suited for high-field applications and consists of a twisted aluminum core and five helical slots. Each slot accommodates a stack of twenty REBCO...
High current superconducting CORC® cable or wire is composed of spiraled HTS REBCO tapes in multiple layers. The cable combines isotropic flexibility and high resilience to electromagnetic and thermal loads. The flexibility of the cable is limited by the critical strain value damaging the REBCO layer in the tape. In order to optimize the manufacture conditions and operating performance, the...
Material scientists have been leading the R&D of coated conductors, and they have been focusing on increasing critical currents and lengths of coated conductors. Thanks to their efforts, long coated conductors with large critical currents are commercially available now. However, when we look back over the history of R&D of low Tc superconductors, stabilization using copper was a breakthrough...
Interconductor contact resistance (ICR) is a key property in determining the stability and current sharing of coated conductor cables. Most coated conductor cables have relatively high contact resistance and low current sharing as fabricated because of surface asperities and the oxide layer that forms on the Cu-stabilizer. Here we work to quantify the induced differences in using three methods...
Spatial homogeneity is one of the most important issues for practical applications of REBCO based magnets. Reel-to-reel Ic measurement is now widely used for the investigation of local Ic variation, however, these measurements are limited at low magnetif field around self-field and at 77 K in most cases, whereas practical operation condistions of superconducting magnets are higher magnetic...
The filamentation of tape shaped RE123-coated conductors is important to reduce the shielding current from RE123 superconducting layer [1] in development of a high-field magnet such as NMR and MRI. In last year, we reported the development of split wire with 16-main-core by electrical separating by bending stress (ESBS) method [2]. In this study, to obtain more main-core, an electrical...
High-temperature superconducting (HTS) tapes are promising materials for developing high-field magnets for fields exceeding 30 T. Therefore, it is important to characterize their properties at high fields, in particular, the critical current, $I_{\rm c}$. One of the promising types of HTS tape is produced by THEVA where the architecture of the tape is unique and simple. Nowadays, these tapes...
High-temperature superconductors are becoming engineering materials, e.g. as commercially available long-length tapes (coated conductors, CCs). Among them, REBa2Cu3O7-x (REBCO, RE rare earth) compounds have emerged as excellent candidates due to their high-field current carrying capacity. Their properties enhance even further when REBCO nanocomposites are formed, i.e., nanoscale...
Due to high flexibilities and high critical current densities, the conductor on round core cable wound with REBCO coated conductors are currently being developed for the next generation of high field magnets. One of the primary challenges in the development of REBCO cable is quench protection, as the cable is prone to be burned out once the quench initiates. However, quench study of REBCO...
A project to develop a Korean-type large scale floating off shore wind power system with a superconducting wind power generator has started. It is an innovative wind power project on the development of high-temperature superconducting (HTS) magnet, test facility, offshore floating system, and network connection technologies for the design of 10 MW class floating offshore wind power system with...
High-temperature superconducting (HTS) materials, including bulks and tape stacks, have shown high current-carrying and field-trapping capacity in previous studies, which makes them employed in the synchronous motors (SMs) as a substitute of permanent magnets (PMs). When used as rotor magnets, hybrid magnets (HMs) made of HTS tape stacks and PMs show remarkable advantages compared with bulks...
Superconducting magnetic levitation (maglev) is developing rapidly in recent decades for its incomparable features like ultrahigh cruising speed. To develop the second generation high tempera-ture superconducting (2G HTS) maglev, a serious of work has been done by us including design of propulsive system, optimiza-tion of 2G HTS magnet system, energizing tests and over-current duration tests....
Linear oscillating machines (LOMs) can control linear reciprocating motions through stroke cycles at specific frequencies. A single-phase, short stroke LOM has been developed for use in refrigeration compressors and other similar devices, because of their high transmission efficiency and simple structure. Generally, conventional LOMs are designed as cylindrical structures. However, such...
Permanent magnet synchronous machines (PMSM) are becoming an essential technology for applications such as home appliances, industrial tools, and electrical vehicles. Todays, consumer demands for noise and vibration of products are increasing, and studies on the noise and vibration characteristics of motors that generate power are actively being conducted. One of the factors contributing to...
In recent years, flux-modulated principle is investigated extensively in diverse permanent magnet (PM) motors due to the prominent advantages of low-speed and large torque capability. And then, a new electrical machine family, nominated as flux-modulated PM (FMPM) motor, is formed gradually. Interestingly, the FMPM motors break through the traditional motor design rule that the pole-pairs of...
This paper presents the research work for a novel dual-stator composite-rotor synchronous machine (DSCRSM). Ferrite permanent magnets (PMs) are used for the composite rotor with flux barriers, while the axis of each PM pole is located as 45 degree (electrical) with respect of the axis of the corresponding flux barrier. Compared with the conventional permanent magnet-assisted synchronous...
Recently, permanent magnet synchronous motors (PMSMs) have been widely used in the industry owing to their various advantages, such as high-speed operation, high efficiency, and compact design. However, PMSMs have the drawback of noise and vibration, which is caused by local force generated by the interaction between the stator and rotor magnets having high magnetic energy, significantly...
Dual mechanical port flux-switching permanent magnet (DMP-FSPM) machine with high power density, high torque density, and wide operation range has potential application prospect in electric vehicles (EVs). The DMP-FSPM machine is consist of inner rotor, outer rotor and middle stator which can be regarded as the combination of two conventional flux-switching permanent magnet (FSPM) machines....
Tubular flux-switching permanent magnet motor (TFSPMM) is a special kind of permanent magnet machine with the permanent magnet (PM) installed on the stator side and there is no winding or PMs on the mover side. Among various kind of linear machines, TFSPMM draws a great interest from researchers for its robust structure, high drive force density and low material cost required. Compared with...
Compared with Linear Induction Motor (LIM) which is widely applied in urban railway transit system, Linear Flux-Switching Motor (LFSM) has the merits of high power density, high efficiency, while the secondary of LFSM is robust and simple. Hence, LFSM is claimed to be promising for urban railway transit system.
Generally, LFSPM can be classified as Linear Wound Field Flux-Switching (LWFFS)...
This paper describes a study on the shape design of Magnetic-geared synchronous Motor for improvement of performance and securing rigidity. The Magnetic-Geared synchronous Motor(MGM) is an all-in-one structure of a magnetic gear and a permanent magnet synchronous motor, and is an electric machinery capable of operating both functions. In this study, the existing surface-mounted type is set as...
1) Introduction
Currently, drones are used in various fields such as logistics, transportation and filming in the military field. However, there is a disadvantage that it is difficult to operate for a long time due to the battery limit of the drone. In order to overcome these disadvantages, studies have been conducted to improve the efficiency of the motor and to increase the power per...
In the past two decades, a bearingless synchronous reluctance motor (BSynRM) was proposed and developed. Besides the advantages of the traditional bearingless motor, the BSynRM has the advantages of simple structure, low cost, low losses and can realize high speed operation using weak magnetic speed regulation. A permanent magnet assisted bearingless synchronous reluctance motor (PMa-BSynRM),...
- Introduction
The BLDC motors(Brushless DC Motors) have been used for different kinds of industries due to the high power density, low maintenance and simple design. BLDC motors are used in variety of applications such as home appliances, electric vehicles and aerospace applications. Recently, aerospace applications like drones raise a demand for a permanent magnet BLDC motor with high...
Permanent magnet (PM) machines have been a research hotspot for EV propulsion due to their merits of high power density and high reliability [1]. Recently, considering the high price and unstable supply of rare-earth PM material, the non-rare-earth PM (NRE-PM) motor has drawn increasing attention. However, the relatively low magnetic energy product of non-rare-earth PM makes it difficult to...
High power motors and generators with compactness and lightweight are required for turboelectric propulsion system for future electric aircrafts. Fully superconducting rotating machines have the potential to realize high power density. In this study, we aim to design high-power-density synchronous motors composed of superconducting field windings and superconducting armature windings,...
High power density motors are required for electric propulsion systems of future electric aircrafts, flying cars and electric vehicles. The highest power density of the conventional motor for aircrafts is reported as 5.5 kW / kg. Superconducting rotating machines have a potential to realize higher power density due to its high current density and low loss property. In this study induction...
EV & HEV are being studied to increase fuel economy and driving efficiency in a variety of ways. Especially, mechanical compressor is critical reason of reducing fuel efficiency. The brushless direct current motor (BLDC) is considered as the most suitable model to satisfy the characteristics of electric compressors. Segmented permanent magnet was used to improve the efficiency of the...
An experimental platform of high temperature superconducting (HTS) synchronous motor with brushless HTS flux pump exciter has been designed and built. The support structure of HTS field windings was designed with a cantilever beam and was manufactured. In this paper, an HTS racetrack coil wound with YBCO tapes was designed and fabricated to verify the reliability of the motor employing a...
Generally, brushless DC (BLDC) motors use three low-cost Hall sensors to obtain information regarding the position of the rotor and operate using a 120° commutation method. Furthermore, BLDC motors require an ideal trapezoidal back-EMF waveform owing to an input current. However, it negatively affects the motor performance owing to the notch phenomenon of current. In addition, torque ripple,...
Linear switched reluctant motors(LSRMs) have received more attention in variable speed drive applications such as urban railway transportation due to their simple structure and minimum use of power switching devices. However, the thrust/power capabilities is not high enough in certain circumstances. To incorporate the merits of simple and robust structure of LSRM and high thrust force density...
Flux-switching permanent magnet (FSPM) machine is extensively investigated own to its advantages of robust motor structure, low torque ripple and high efficiency. Recently, considering the high price and unstable supply of rare-earth PM, less-rare-earth or none-rare-earth PM motors have drawn increasing attention. Due to the relatively low magnetic energy product of non-rare-earth PM, the...
Recently, flux-modulated permanent magnet (FMPM) motors which based on flux-modulation principle have been extensively investigated, due to inherent high torque density at low speed. With the increasingly critical operating environments for traction machines, high-reliability operation of machines has gained much attention. Especially when traction machines operate under extreme conditions,...
Finite Element Method (FEM) modeling of stability and current sharing in Nb3Sn Rutherford cables was performed. The modeled cables had 32 strands and they were three twist pitches long. Different values of contact resistances Ra and Rc were selected based on previous values extracted from ac loss measurements, as well as a set of design values. Current sharing was then projected for these...
The superconducting dipole magnet for the Compressed Baryonic Matter (CBM) experiment at FAIR houses the Silicon Tracking System (STS), and provides a magnetic field integral of 1 Tm which is needed to obtain a momentum resolution of Δp/p = 1% for track reconstruction at FAIR beam energies. The magnet gap has a height of 140 cm and a width of 250 cm in order to accommodate the STS with a polar...
The High Intensity Heavy Ion Accelerator Facility (HIAF) is a new engineering project proposed by Institute of Modern Physics of China. Superconducting magnets will be used as part of the accelerator magnets. When operating at fast-pulsed cycled mode, the superconducting cable will dissipate power (AC loss), which affects the stability of magnet. The main contribution of the AC losses in...
With extremely high critical current density (Jc) and excellent strain tolerance, Nb3Al superconductor is considered as an alternative to Nb3Sn for application of high-filed magnets. However, complexity in the phase formation of Nb3Al hinders the Nb3Al superconducting wires to satisfy the requirement of engineering applications at present. Here, we have reported the improved performance of...
National Institute for Fusion Science (NIFS) in Japan is considering about FFHR-d1 (Force Free Helical Reactor) for their future R&D project. Its magnet system will be needed a pair of helical typed coils with the major radius of 15.6 m. Since the maximum magnetic field on the helical coil of FFHR-d1 reaches 11.9 T, the NbTi cable is not applicable. The practical Nb3Sn cable was selected...
This work compared the phase structure and superconducting properties of RHQT Nb3Al wires fabricated by static and reel to reel (R2R) rapidly heating and quenching conditions. The time for static and dynamic heating of the wire is 0.8s and 0.4s. Rapid heating current (IRHQ) of 67A~69A for static RHQ and 120~122A for R2R dynamic RHQ can fabricated ductile precursor wires and obtain single phase...
In order to develop future particle colliders such as the HiLumi - Large Hadron Collider (HL-LHC) and the Future Circular Collider (FCC), high field superconducting Nb3Sn magnets are necessary. Following the winding, the conductor requires a heat treatment at 650 °C during which significant dimensional changes occur. If dimensional changes are not allowed by the tooling, mechanical stresses...
The advantages of superconducting Rutherford cables are that it can reduce the inductance and increase the stability of superconducting magnets. Due to its high critical field strength and high current carrying capacity Nb3Sn Rutherford cable is one of the best choices for making high field accelerator superconducting magnets. But Nb3Sn superconducting wire has poor mechanical properties and...
U.S. Magnet Development Program (MDP) has developed a 15 T Nb3Sn dipole demonstrator for a post-LHC pp Collider. The magnet design is based on 60-mm aperture 4-layer shell-type coils, graded between the inner and outer layers to maximize the magnet performance. The cable in the two innermost layers has 28 strands 1.0 mm in diameter and the cable in the two outermost layers has 40 strands 0.7...
ABSTRACT BODY:
HTS tapes, because of their widths and large shape aspect ratios, have not been readily manufacturable into Rutherford or Roebel cables, even though these kinds of cables are required for many large coil applications. A type of transposed Roebel cable is under development with 2G tape, but its design flexibility is very limited, and its processing very complex, as well as...
Neurospin is a neuroscience research center located in France at CEA Saclay. The facility is already hosting several MRI magnets and Iseult, an innovative Whole Body 11.7 T MRI system, will be available very soon. The core part of Iseult is an actively shielded NbTi magnet cooled with a superfluid helium bath at 1.8K, that will provide a homogeneous field of 11.7 T within a 90 cm warm bore....
Advanced Conductor Technologies is developing high-temperature superconducting Conductor on Round Core (CORC®) cables and wires wound from REBCO coated conductors for use in high-field magnets. Magnet applications on which the conductor development is focused on include compact fusion magnets that operate at currents between 50 and 100 kA at fields of 12 – 20 T and accelerator magnets that...
Within the US Magnet Development Program (MDP) a 15 T Nb3Sn dipole was developed, to demonstrate a magnet design for a post-LHC pp Collider. The magnet design is based on 60 mm aperture 4-layer shell-type coils, graded between the inner and outer layers to maximize the magnet performance. The cable in the two innermost layers has 28 strands 1.0 mm in diameter and the cable in the two outermost...
Brookhaven National Laboratory (BNL) is building a 25 T, 100 mm cold bore HTS solenoid for the Center for Axion and Precision Physics (CAPP) at the Institute for Basic Science (IBS) in Korea to be used in their search for Dark Matter Axions. The magnet is wound using - Second Generation (2G) High Temperature Superconductor (HTS) tape from SuperPower. The combination of high magnetic field (>20...
F2D2, the FCC Flared-ends Dipole Demonstrator, is a 15 T single-aperture short model being developed within a collaboration between CEA Paris-Saclay and CERN. The design phase is ongoing at CEA; the magnet will be fabricated at CEA and then tested at CERN. The 2D magnetic and mechanical designs have been optimized previously and allowed defining the operating points and the required structural...
The use of REBCO inner coils is a promising option for developing high-field magnets since the coil can be designed at high-hoop stress typically at >400 MPa. Such a coil, however, sometimes suffers from the appearance of a normal voltage even at medium hoop stress such as 200 MPa, i.e., unexpected degradation [1]. We believe that those degradations are caused by strong electromagnetic forces...
Research and development for the practical application of a medical-use magnetic resonance imaging system (MRI) superconducting magnet that requires without liquid helium started as the New Energy and Industrial Technology Development Organization's (NEDO) supported project in fiscal 2016. Development of a liquid helium-free medical MRI superconducting magnet is desired. Another purpose is to...
High field superconducting magnet technology is the key to the success of the high energy particle accelerators. China is pursuing high field magnet R&D for future particle colliders like the Super Proton Proton Collider (SPPC). SPPC will need thousands of high field (12-20 T) superconducting magnets in around 20 years. A long term R&D roadmap of the advanced superconducting materials and high...
Rare Earth-Barium-Copper-Oxide (REBCO) coated conductor (CC) tapes are promising conductors for high energy and high field applications. In the case of epoxy-impregnated REBCO superconducting coils, however, excessive transverse stresses generated from cooling, and Lorentz forces on the CC tapes can cause delamination, resulting in reductions in the load-carrying capacity as well as...
Coils for rare-earth barium copper oxide (REBCO) high temperature superconductor (HTS) magnets are often wound with insulation between turns (i.e. effectively infinite resistance). In this case, magnetic field generated by the coil is linearly related to the transport current in the coil, allowing voltage-limited magnet ramping. However, quench protection has been shown to be hard to...
High field dipole magnets with common-coil configuration are under development at IHEP (the Institute of High Energy Physics, Chinese Academy of Sciences) for key technology pre-study of high energy colliders like SPPC (Super Proton-Proton Collider). A model magnet named LPF1 has been fabricated and tested in 2018, which was made up of 4 flat racetrack NbTi coils and 2 flat racetrack Nb3Sn...
Recently, we developed a superconducting joint between two multi-filamentary Bi2223 tapes with the joint by incongruent melting (JIM) method [1]. During the incongruent melting process, Bi2223 phase is separated to Bi2212, Bi2201, and liquid phases. Since the Bi2212 is also high-temperature superconductor, the superconducting joint can be obtained without recrystallization of Bi2223 from the...
In this study we performed magnetic, mechanical and thermal modeling of a 3T actively shielded whole body MRI (Magnetic Resonance Imaging) magnet. The final design had an overall magnet length and conductor length which can lead to conduction cooled designs which are comparable to NbTi helium bath cooled 3 T designs. The design had a magnetic field homogeneity better than 10 ppm...
For realizing HTS magnets equipped with a persistent current circuit, the development of superconducting joints between HTS tapes with enough large current capacity in external magnetic fields is indispensable. On the other hand, the Ag-sheathed Bi2223 (Bi2223/Ag) commercial tapes, DI-BSCCO, show high critical current (Ic) characteristics of ~ 200 A at 77 K in self-field and...
In this paper, we present construction and persistent-mode operation results of a half-scale 1.5-T/54-mm room-temperature bore MgB2 MRI-quality magnet for the development of a tabletop “finger” MRI system. A half-scale magnet, composed of 5 coil sections and a persistent-current switch, was wound with a single ~590-m long unreacted/monofilament MgB2 wire having a...
New high temperature superconductor (HTS) technology is actively being pursued to achieve fields beyond those available with the present Nb3Sn technology (~23 T). In an effort to further drive Bi2Sr2CaCu2O8-δ (Bi 2212) round wire technology, better understanding of the performance of coils wound with this conductor is paramount. Work presented in this body demonstrates that the limiting strain...
This paper presents the design of a high field and portable MRI magnet system for the rapid and early diagnosis of brain trauma. Early diagnosis and therapy stratification can reduce the risk for critically brain ill patients with the use of near patient imaging, and can aid with precision medicine. High temperature superconductors have the ability to carry large currents at higher...
This paper reports a design and performance estimation of a 20 T no-insulation (NI) high temperature superconductor (HTS) standalone user magnet currently being developed at the National High Magnetic Field Laboratory. It consists of a stack of 17 double pancake coils wound with tapes from two different vendors, SuNAM and SuperPower, in consideration of their complementary in-field critical...
This paper presents our analysis of the electromagnetic characteristic and thermal stability of 2G high-temperature superconductor (HTS) pancake coils depending on the turn-to-turn contact resistance. Numerical simulations for investigating electromagnetic characteristic, mechanical stress and thermal stability of HTS pancake coils were performed by taking into account different contact...
This article analyzes the charging behavior of no-insulation high temperature superconducting (HTS) ReBCO double-cake coils under conduction cooling and liquid nitrogen cooling in detail. A partial equivalent circuit model of a determined parameter ReBCO coil is applied to evaluate charging behavior under different cooling conditions. At the same time, the finite element method is used to...
This paper is to study the practical critical current of No-insulation (NI) high temperature superconducting (HTS) coils under local heat disturbances. Based on a multi-physics model that built from an electric network model, a thermal coil model and a magnetic field model, behaviors of a HTS coil under different currents and heat disturbances are compared in this paper. A balance model of HTS...
The no-insulation (NI) method has provided dramatic progress on the high-field magnet technology in the last decade. An NI REBCO pancake coil can operate at a very high current density supported by a self-protecting behavior. However, it was recently demonstrated that asymmetric distributions of axial forces due to electromagnetic forces during the quench propagation results in serious...
Recently, we have reported that screening currents in REBCO high field magnets may be a source of large electromagnetic stresses and consequently cause mechanical damage to the superconducting tape. To better estimate the electromechanical behavior of a REBCO magnet even in the initial design stage, we have modeled the distribution of screening currents in an NI REBCO magnet and compared the...
Due to the special rectangular cross section of the REBCO tapes, the screening current-Induced magnetic field (SCIF) in a REBCO high temperature superconducting (HTS) coil will deteriorate the spatial homogeneity and temporal stability of the superconducting magnet, which is a key issue for the application of HTS magnets in the Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging...
The NHMFL has commenced with the development of an all-superconducting 40 T magnet that will be installed in its DC-Field User Facility. At present various high temperature superconductor technologies are being investigated as candidates for the magnet construction. It is the objective of this early development stage to address questions regarding the application of a type of superconductor...
Tokamak Energy are developing large scale REBCO HTS magnets for application in spherical tokamaks for fusion energy. As part of our HTS technology development plan, a series of quality assessment (QA) coils have been manufactured and tested. These are non-insulated coils containing ~100 m of HTS tape. The manufacture and testing of these magnets has allowed us to assess the performance of HTS...
The National High Magnetic Field Laboratory (NHMFL) has successfully operated its 20 Tesla 195mm large bore magnet for over 20 years. Eventually, as there was a certain slowdown in demand for that magnet at the time, it had been decommissioned in 2016 and its two outer coils have been re-used for parts in a higher energy density configuration to facilitate the fast construction of the word...
The High Field Magnet Laboratory of the Radboud University is constructing a 45 T hybrid magnet system. The hybrid magnet is being assembled in one of the six cells of the Nijmegen laboratory. The resistive insert magnet will be energized with the 40 kA, 550 V power converter installed at the HFML.
This paper provides details of the electromagnetic and thermal coil design of the resistive...
The High Field Magnet Laboratory of the Radboud University is constructing a 45 T hybrid magnet system. The measures taken to accept the largest fault forces that can result in the not so unlikely event of failure of parts of the resistive insert magnet, dominate the design of the support structures, in particular those coupling the room temperature resistive insert magnet with the...
The 40T hybrid magnet in Hefei consisting of a 10 T superconducting outsert and a 30 T resistive insert magnet has passed the national evaluation in 2017 and has been running steadily up to now. The thermal shield cooled by liquid nitrogen sandwiched by the superconducting magnet and the water-cooled resistive magnet is the important component of the hybrid magnet. During the debugging phase...
Abstract—As a marvelous promotion of applications with HTS magnet in a variety of fields appears, it is of particular importance to compensate persistent current decay in HTS magnets. Therefore, a large quantity of means of contactless power supply (CPT) have emerged in endlessly. In general, CPT mainly consists of 5 parts, which include power, inverter circuit, electromagnetic inductive...
In High Temperature Superconductor (HTS) direct current (dc) magnet applications much of the cryocooler load required for continuous operation is imposed by the external current leads. Operation of HTS dc magnets at high currents requires large cross-section leads, but these leads provide a large thermal bridge between the ambient current supply and the cryogenic superconducting components....
In general, superconducting rotating machines have been widely deployed because they have advantages such as smaller volume, lighter weight, and higher efficiency than conventional rotating machines. However, superconducting rotating machines need a cryogenic system to keep field coils in a superconducting state. High temperature superconducting (HTS) flux pumps inject DC current into...
High temperature superconductor (HTS) magnet working in persistent current mode (PCM) shows great potential in improving the efficiency of electrical applications, since it can offer amazing merits in lowering the energy cost and realizing the compact and light weight design of electrical devices. Unfortunately, the lossless PCM HTS magnet is unavailable due to the non-ignorable joint...
High-temperature superconducting (HTS) coils wound without turn-to-turn insulation (NI coils) show excellent electrical and thermal performance compared to HTS coils wound with insulation material (INS coils). However, charging the NI coils using a direct current (DC) power supply have a slower charging time than the INS coils. To overcome this slow charging time, research is underway to...
Though an HTS jointless coil can conduct a persistent current without decay, it needs an external power source for the excitation. We have magnetized the HTS jointless coils by field cooling and also have excited by flux pumps with rotating permanent magnets. A stationary flux pump has several comparative advantages over the field cooling or the rotary flux pump.
In this paper, we designed...
Abstract
A facility capable of testing superconducting cables with current of tens of kA is essential for the development of large superconducting magnets. A superconducting transformer (SCT) is a suitable choice as a high DC current source for testing superconducting cables. In this work, we will present our experimental results of a SCT that was originally developed by Lawrence...
JT-60SA is the second largest tokamak device constructed in the world, which is being implemented aiming to start the first experiment in 2020. One of the most important features of JT-60SA is to have superconducting magnets for long-pulsed plasma discharge (100 s flattop). JT-60SA has ten of poloidal field (PF) coils for inductive current drive and shape control of a plasma. Their stored...
Water-cooled resistive high-field research magnets require a high power supply with an extremely high current stability, and a low current ripple and noise. The conventional resistive magnet power supply uses thyristor rectifiers, followed by a passive filter and an active filter in series to reduce the voltage ripple. This Paper describes a new circuit topology design of the resistive magnet...
The high stability flat-top pulsed magnetic field (FTPMF) is strongly needed for some scientific researches such as nuclear magnetic resonance (NMR) and specific heat measurement. The high stability FTPMF Facility based on the battery power supply with a linear bypass circuit had been built at Wuhan National High Magnetic Field Center the in 2018. The linear bypass circuit mainly consists of...
In the past years, the thyristor converter technology has been adopted in the Tokamak coil power supply, mainly because of current carrying capacity and overload capability of thyristor with high power level. However, thyristor converter technology also has inherent defects, including poor dynamic control, low power factor, and producing a large number of reactive power and harmonics that...
The Superconducting FRagment Separator (Super-FRS) at FAIR being built in Darmstadt, Germany, foresees a significant increase of momentum acceptance and angular acceptance of the secondary particle beams compared to the current facility of Fragment Separator (FRS). This requires dipoles and multipole magnets with a large aperture. Consequently, superferric magnets will be installed except for...
For the FAIR project`s SIS100 Synchrotron a series of 110 fast ramped dipoles is currently built and in addition a total of 83 superconducting quadrupole doublet modules (QDM) are needed for this accelerator.
An intense measurement program of the first of series (FoS) dipole revealed excellent behavior with respect to, e.g., quench performance and AC losses. With an optimized fabrication...
The Facility for Antiproton and Ion Research (FAIR), currently being built in Darmstadt (Germany), needs 21 standard superferric dipoles for its Superconducting FRagment Separator (Super-FRS). The dipoles manufacturing contract has been awarded to Elytt (Spain) in Spring 2017 and CEA Paris-Saclay (Commissariat à l’Energie Atomique) is overseeing the design and manufacturing activities in the...
The new international accelerator facility FAIR (Facility for Antiproton and Ion Research) is currently under construction in Darmstadt, Germany. The core component of the complex is the heavy ion synchrotron SIS100 which utilises 417 superconducting magnets assembled in 191 cryo-magnetic modules. The SIS100 machine is supplied with two phase helium via 52 local cryogenic components. All...
The beam separation dipole, MBXF, is being prepared by the High Energy Accelerator Research Organization, KEK, for the high luminosity LHC (HL-LHC) upgrade. The new magnet is designed to generate a central field of 5.6 T at the nominal operating conditions of 12.05 kA and 1.9 K. From the past design study, the magnet is designed as a single layer coil wound with a 15 mm wide NbTi/Cu Rutherford...
The Large Hadron Collider (LHC) upgrade, called High Luminosity LHC (HL-LHC) is planned for the next decade. A set of twin aperture beam orbit correctors positioned on the approaches to the ATLAS & CMS experiments will be development. The orbit corrector based on Canted Cosine Theta (CCT) design to achieve 5 Tm field integral and multipoles lower than 10 units in the twin aperture. Tow...
The new D2 recombination superconducting dipole is a key two-in-one NbTi magnet with a 105 mm bore aperture for the LHC high luminosity upgrade project (HL-LHC) expected in operation from 2024. A short model magnet of 1.6 m magnetic length has been designed by INFN (Genova), built by Ansaldo Superconductors Group, and cold tested at CERN within a INFN-CERN collaboration framework. This model...
The LHC beam separation dipoles plans to be replaced for the high luminosity LHC (HL-LHC) upgrade. The new separation dipole, MBXF, is based on the Nb-Ti superconductor, and is designed to generate 35 Tm at the nominal operating conditions of 12.05 kA and 1.9 K. The magnet has a stored energy of 0.34 MJ/m, and all the energy needs to be extracted only by quench protection heaters before the...
In the Large Hadron Collider (LHC) at CERN, it is expected that 35 out of the 122 MCBC and MCBY orbit corrector dipoles will receive up to 20 MGy of gamma radiation over the High-Luminosity (HL)-LHC lifetime. Since these magnets were not designed to withstand such high gamma doses, new MCBC and MCBY magnets have to be designed and produced using radiation hard impregnation insulation and...
The LASA Laboratory (INFN, Milan) is working in the High Luminosity LHC program for developing, in collaboration with CERN, 6 different types of High Order corrector magnets. In this framework, in parallel with a conventional design of superferric magnets with LTS conductor, the LASA Lab. is focusing on the research of novel superconducting materials which may have application in particle...
This paper presents an analytical method that fines the mutual influence of the magnetic field in a dipole magnet. A vacuum beam tube is in thermal contact with a cryogenic cooling pipe for a high-quality vacuum. These two different geometric components have different eddy current profiles. And the corresponding magnetic fields disturb the operation field quality. The cooling pipe in an...
Based on the collaboration of Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) and Russia Joint Institute for Nuclear Research (JINR) for proton therapy, a 200 MeV compact superconducting proton cyclotron project (SC200 project) has been launched at ASIPP since 2016. The superconducting magnet is the most critical and challenging subsystem for the cyclotron to provide ~3 T...
Accelerator Driven System (ADS) is recognized as one of the most efficient ways to transmute minor-actinides. China initiative Accelerator Driven System (CiADS) project as ADS demonstration with 500 MeV has been approved in 2015. Three type superconducting focusing solenoids are used to focus and correct beam in CiADS superconducting LINAC. The focusing solenoid includes a solenoid coil and a...
AC loss is one of the important considerations in the design and operation of high temperature superconducting (HTS) devices. Traditional method to measure AC loss generated in HTS coil is to measure the coil voltage’s resistive component by using a lock-in amplifier. This method has several limitations during application. In order to solve these problems, integration method and energy...
In a high-temperature superconducting (HTS) multi-layer AC cable, the HTS tapes of one layer are twisted cylindrically, an AC transport current is provided, and the cable is exposed to an AC magnetic field produced by the other layers. The magnetic field consists of a circumferential magnetic field and a longitudinal magnetic field. The circumferential magnetic field is produced by a transport...
The long-life driving coil is the prerequisite for Electromagnetic forming industrial application, so far, the temperature rise is one of the major factors that restraint its working life. This paper proposes a new coupling cooling method of driving coil by placing extra cooling coil with timing control system on the other side, which can reduce the Joule heating and temperature rise of the...
The Super High Momentum Spectrometer (SHMS) of Hall C, part of the recent 12 GeV accelerator Upgrade at Jefferson Lab, was successfully commissioned in 2017. During pre-commissioning, fast dumps of the SHMS Q2/Q3 quadrupole and Dipole superconducting magnets experienced some level of operational difficulty. Measurements and analyses demonstrate that the fast discharge caused fast current...
Copper losses and iron losses are the two most significant losses in electrical machines. The iron loss is a large portion of the total losses, and it mainly influences efficiency. The copper losses are relatively easy to calculate and it will be negligible if current is too small; on the other hand, the calculation methods of iron losses are more complicated than the copper loss calculation....
During operation, AC loss of central solenoid (CS) coils can be quite significant. From cryogenic point of view, CS coils, made of cable-in-conduit conductors (CICC’s), can be regard as porous pipes. A common way to estimate the heat generated by AC loss is from a difference in the enthalpy flow between the inlet and outlet. In actual cases, offsets in the enthalpy flow difference commonly...
Abstract—Conductor-on-round-core (CORC) cable, which is helically wounded by YBCO coated conductors, has become a promising candidate conductor for high temperature superconducting (HTS) applications, such as superconducting magnets and electric machines. Understanding the mechanism and magnitude of AC loss is extremely critical for the design of CORC cable. Dynamic resistance has been...
Understanding AC loss in High Temperature Superconductor (HTS) magnets is critical to application. The common methods for AC loss measurement are electrical and calorimetric measurements. It is generally accepted that calorimetric techniques are superior to electrical methods when there is a phase difference between the transport current and external magnetic field. A common challenge in...
We have been studying the potential of energy consumption reduction in rapid cycling synchrotrons (RCSs) by using superferric magnets with high temperature superconductor (HTS) coils. In our previous research, we developed a three-dimensional electromagnetic field analysis model for superferric magnets, and analyses were conducted on superferric magnets in several kinds of RCSs designed for...
Neodymium (Nd) magnets have been applied for a traction motor owing to its considerable maximum energy product. In addition, heavy rare earth elements such as Dysprosium (Dy) are added to the Nd magnets for withstanding severe conditions of a traction motor that includes high temperature and strong demagnetizing field. However, the employment of Dy causes critical issues regarding...
As a promising member of permanent-magnet brushless motors, flux-modulated permanent-magnet (FMPM) motors have aroused considerable attentions due to the outstanding low-speed large-torque characteristics. With the increasing demands of high quality PM motor, the high efficiency transmission in motor operation is one of the important performance evaluation indexes of motor. And then, the...
This paper presents the design of Electric outboard Permanent Magnet(PM) motor driven at a rated output and speed of 2.5 kW and 3,000 r/min, respectively, for use in small leisure boat. The PM motor for electric outboard motors is located below the water surface and it is necessary to set the proper PM operating point in consideration of the fact that the water cooling can be applied. In...
A permanent magnet synchronous machine (PMSM) has the advantages of simple structure, high power density and high efficiency, without the excitation winding and its loss. However, the magnetic field in PMSM is difficult to be regulated, due to its excitation by permanent magnet (PM), which leads to limited constant power speed range (CPSR) as a motor and/or confined voltage regulation capacity...
Flux-modulated permanent magnet (FMPM) motors have been considered as a promising candidate in the direct drive application due to the superior torque performance in the low speed condition. Yet, the output torque capability of the FMPM motor generally relies on the expensive rare earth permanent magnet (REPM), which is same to the conventional permanent magnet motor. It greatly limits the...
Comparative study of a 5kW novel modular multistage axial flux permanent magnet machine (MMAFPMM) is carried out. The mentioned MMAFPMM has three rotors and two stators. The rotors and stators are arranged in axial direction alternately and the two sets of windings are independent. So there are different forms to adopt the different operating conditions. They can work in respective,...
Traditional linear machines are under great influence of end effect because of their finite stacking lengths in transverse and longitudinal directions. Transverse end effect will produce a lot of flux leakage enclosed with air. Longitudinal end effect will cause imbalance of phase performance so that linear machine’s force fluctuation is aggravated. In this paper, a novel tubular switched...
The double-rotor hybrid excited axial switched-flux permanent magnet (PM) (DR-HASFPM) machine is a novel hybrid excited machine with single stator and double disk-type rotors. The double rotors have same structure without PMs and windings. The stator contains 6 doubly-H-shaped cores and 6 interlaced magnetized PMs. The PMs are sandwiched between the two doubly-H-shaped cores, where the...
The bearingless flux switching permanent magnet (BFSPM) motor integrates the advantages of magnetic bearings with no mechanical wear, no lubrication, high speed and high precision, long service life, etc., as well as inherits some merits of flux switching permanent magnet motors with fast heat dissipation, low demagnetization risk, high critical speed and so on. In recent years, it has...
Flux switching permanent magnet machine (FSPMM) is a new permanent magnet machine, with installing permanent magnet (PM) in between of adjacent stator tooth to form good flux concentrating structure and there is no windings or PMs on rotor core. Claw pole machine (CPM) is a special kind of transverse flux machine (TFM), compared with TFM the CPM can have higher torque ability and power factor,...
Interior permanent magnet synchronous motors (IPMSM) are widely applied to various industry applications such as electric vehicle, wind power generator, industrial servo motor, and home appliance due to advantage of wide speed range, high power density, high efficiency and excellent control performance. To realize a high performance and reliable IPMSM drive system, the exact knowledge of the...
In recent years, researches on high output and high efficiency of electric devices in all industries have been actively carried out due to strengthened regulations on energy consumption and environmental pollution worldwide.
In order to achieve high power efficiency and high efficiency in the motor industry, it was mainly used for rare earth motors using rare-earth magnets with high energy...
Due to the advantages of simple rotor structure and ease of PMs temperature regulation, stator permanent magnet (PM) motors have been attracted more and more attention. A doubly salient PM motor with Π-shaped stator iron core segments (Π-core DSPM motor) has been proposed, of which the special operating principle was explained by the principle of magnetic field modulation and the magnetic...
This paper proposed a 3D magnetic equivalent circuit (3D MEC) method to analyze the flux linkage characteristics of double-sided switched reluctance linear motor (DSRLM). Firstly, the 3D finite element model (3D FEM) of DSRLM is established to analyze the magnetic field line distribution of the motor. Then, the magnetic field distribution of two representative positions (unaligned and aligned...
As the complexity of modern industrial drive systems, the two degree of freedom (2-DOF) movement is needed in many industry drive applications. In this paper, a double stator linear rotary permanent magnet machine (DSLRPMM) which features linear and/or rotary movements is investigated. The motor is constituted of two stators and a hollow mover with permanent magnets (PMs) affixed on its...
As increasing of rare earth permanent magnet motor usage, IPMSM(Interior Permanent Magnet Synchronous Motor) is used in many industrial region. As used in many industrial region. researches on increasing power, efficiency and stiffness are under way. Most of these researches are interpreted as 2D model. If interpreted in 2D model, phenomenons which occur on axial direction are not considered....
The interior permanent magnet synchronous motor (IPMSM) has a promising prospect in electric vehicle because of its advantages of high power density, high torque density, high efficiency and good flux weakening ability. With the improvement of motor power and performance, shaped permanent magnet (PM) pole rotors like V-type, U-type and other structures appear. The device complexity and...
Drive motors for hybrid electric vehicles (EVs) have often been studied to increase their efficiency and improve the total driving distance on a single charge. The motors are required to operate over a wide operating speed range according to operating characteristics of HEVs, which should improve the efficiency in the frequent operating range. To achieve this improvement, this paper presents...
The brushless direct current motor (BLDC) is considered as the most suitable model to satisfy the characteristics of electric compressors. Segmented permanent magnet was used to improve the efficiency of the electric-driven compressor of electric vehicles motor. It is one of the methods for reducing the eddy current loss. The thermal characteristics of the motor are analyzed according to the...
This paper presents the basic investigation results on electrical and thermal characteristics of second generation high temperature superconducting race-track coil (2G HTS RTC) under external time-varying magnetic field. This RTC is electrically and thermally insulated by a vanadium III oxide (V2O3), which is one of the metal-insulator transition (MIT) materials and has a variability in the...
This paper proposes a heretofore unestablished process to calculate the operating current of a ReBCO coil based on the electrical stability of smart insulation (SI) ReBCO coil. The nonhomogeneity of the critical current (IC) of the ReBCO coated conductor (RCC) makes the calculation of the coil IC from the IC-B-T data of a short sample difficult. In addition, at the determining the operating...
Recently, the NI winding technique has been actively investigated to be used in HTS magnets because this technique enables the coils to become lighter and smaller than that of conventionally insulated counterparts. However, the charge–discharge rate of the NI coil is considerably higher than that of completely insulated coils due to the absence of insulation resistance. In this study, we...
Despite the extensive research on a conduction cooling system, liquid helium (LHe) was still used as a cryogen to cool down the superconducting magnets due to the high-temperature deviation and mechanical vibration of this cooling system. However, in a quench event, the superconducting magnet that utilizes LHe may also exhibit temperature deviation within the magnet because the innermost turns...
No insulation (NI) winding technique using a REBCO wire is considered as a feasible option to develop a high field magnet due to its excellent electric and mechanical stability. A NI magnet shows strong thermal and electromagnetic stability in case of quench, however, it also has charging delay due to leak currents and additional resistive loss through turn-to-turn winding contacts. The...
A coil without turn-to-turn insulation, called a no-insulation (NI) coil has been developed. The NI winding technique has been reported to be a promising method of quench protection. In order to apply the NI winding technique to a conduction-cooled REBCO coil, we developed a coil using an electrically conductive epoxy resin. The electrically conductive epoxy resin in which a metal power was...
The DC superconducting energy pipeline has the advantage of integration of power and fuel, in which the superconducting cables are cooled by liquefied natural gas (LNG) coolant. As one of the newly developing technology of superconductivity in power system, the integrated delivery has the superiority that its total efficiency of energy transportation could reach 96%, for the power loss is only...
High-field split solenoids requirements for beamline applications have become increasingly demanding and an area of significant development in magnet engineering. A number of new magnet designs have been developed utilizing the high current density achievable in modern Nb3Sn superconductors. The magnets described are custom designed for individual experimental applications and have unique...
In this presentation, the concept of a Hybrid Trapped Field Magnet Lens (HTFML) is described, which exploits two different characteristics of type II superconductors: the “vortex pinning effect” of an outer superconducting bulk cylinder, which acts as a trapped field magnet (TFM) using field-cooled magnetization (FCM), combined with the “diamagnetic shielding effect” of an inner bulk magnetic...
Combined with the design of magnetic properties measurement structure and high frequency transformer, the traditional copper stranded wire windings increase the design demand of the core window area to limit the improvement of measuring device. The kind of winding has many turns leading to an increase in inductance. In this paper, an improved windings design method is proposed to optimize the...
An MgB2 superconducting magnet for X-band (12 GHz) Klystrons has been designed, manufactured and tested. According to a CLIC-380GeV staging scenario at CERN, about 5000 sets of klystrons will be used. The Klystrons need electron beam focusing solenoid magnets, and the power consumption of 5000 magnets using Cu conductor is estimated to be 100 MW in case. This MgB2 superconducting solenoid...
This article investigates the main parameters influencing the joint strength of tubular components by electromagnetic compression, more specifically interference-fit (force-fit) by crimping tubes into mandrels. The mechanical parameters considered in this analysis are the remaining residual stress on the mandrel, the joining area and its shape, and the interfacial friction coefficient between...
Stirring casting is one of the most commonly used fabrication processes for particle-reinforced aluminum matrix composites (PRAMCs). It includes mechanical stirring and electromagnetic stirring. Compared with the former, electromagnetic stirring has advantages of non-contact, flexible force loading and so on. However, the structure of traditional electromagnetic stirrer (EMS) is similar to the...
This paper deals with the design and fabrication of a laboratory electromagnet utilizing high temperature superconducting (HTS) coils which is applied to excitate high magnetic fields compared with the conventional laboratory electromagnet with copper coils. The proposed electromagnet was composed of iron-core, HTS coils, and cryostat for the HTS coils. The components are designed using...
This work was performed as part of the international Project 8 collaboration. The goal of the Project 8 experiment is to measure the absolute neutrino mass using tritium beta decays, which involves precisely measuring the energies of the beta-decay electrons in the high-energy tail of the spectrum.
To achieve its design sensitivity of $m_\beta\sim$ 40 meV, Project 8 has chosen an...
Usually, the electromagnetic trip unit in AC circuit breaker has only one trip current value. When a current in circuit is greater than the trip current, the electromagnetic trip unit will be released, so it is suitable for instantaneous tripping in the case of short circuit. In this paper, a novel electromagnetic trip system with two trip current values is studied, which is suitable for...
Induction heating is essentially the use of electromagnetic induction in the conductor of eddy current heating to achieve the purpose of heating the workpiece, with fast, clean, convenient for surface and local heating, and in most cases energy-saving advantages. Compared with the traditional AC induction heating process, the superconducting DC induction heating device uses superconducting...
This paper introduces a novel method of frequency measurement of terahertz (THz) wave with the high magnetic field technology. According to the Zeeman Effect, the magnetic field and frequency are linear, so we can convert the measurement of frequency into the measurement of magnetic field strength by this method. Two magnet systems were used in the experiment, one of them is a pulse magnet...
Abstract—a Space-Time-Controlled Multi-Stage Pulsed Magnetic Field (Stic-Must-PMF) forming and manufacturing technology is introduced in Wuhan National High Magnetic Field Center, the technology is based on spatially strategically placed multiple coil systems and each coil can be addressed individually by its associated power supply with precise timing control. Such well-designed space-time...
Gyrotron is a promising source of high-frequency, high-power RF radiation for plasma heating, ESR spectroscopy, new medical technology and so on. The magnetic field system, which controls the trajectory of the electron beam and the cyclotron frequency of electrons at the resonator cavity, is one of the key parts of the gyrotron. According to the theory of electron cyclotron masers, an 800 GHz...
We constructed a long and flexible solenoid coil by winding a thin, enameled wire around a slightly thicker enameled wire. The structure of this flexible solenoid resembles that of a string of a guitar or a piano. The flexible solenoid is wound on a torus in toroidal direction.
A usual toroidal coil winds the winding in the poloidal direction, but our coils are wound in the toroidal...
Due to its high efficiency and uniform deformation force, the uniform pressure actuator (UPA) is a potential electromagnetic forming (EMF) technology for shaping of mesoscale dimensional metals, such as metal bipolar plates. However, because of its complex structure, the current simplified two-dimensional model or three-dimensional model cannot fully reveal the law and characteristics of UPA,...
In order to solve the problem that the traditional gas wiping method cannot meet the needs of high-speed production, the oxidation and atomization of zinc liquid which not only wastes zinc, but also disperses zinc into the air to pollute environment, a three-phase electromagnetic wiping based on traveling wave magnetic field is proposed. By using a three-phase coil, a traveling wave magnetic...
Under the earth magnetic field, ferromagnetic equipments on a naval ship are magnetized, and accordingly they are apt to cause a local field disturbance underwater. To mitigate such magnetic field for ship’s safety, modern vessels are usually equipped with a degaussing system. In order to minimize the underwater field anomaly, individual coil currents are elaborately tuned, and so there are...
REBCO coated conductor has been regarded as one of the most viable high-temperature superconductor (HTS) options for next-generation high field magnets, mainly owing to its large in-field current carrying capacity and higher mechanical strength. To explore REBCO coil technology, a small-scale REBCO coil was designed, fabricated and tested. The REBCO coil has a winding inner diameter of 15 mm,...
We propose a model of the spherical vector-potential coil, and we investigate the properties of the coil especially the uniform distribution of vector potential. The model is designed base on a spherical winding which made by the long flexible thin solenoid. When we apply a current to a very long solenoid coil, it creates a magnetic field within the coil only; there is no magnetic field...
As the pellet injection for the fuel of the Large Helical Device (LHD), a pneumatic pellet injection is generally used. Although this method injects some pellets made of frozen hydrogen gas into a plasma of the LHD at the velocity of 1.2 km/s, the pellet does not reach the plasma core. For this reason, this method is not efficient in the fuel supply.
Recently, a novel pellet injection...
Insulated core transformer (ICT) electron accelerator offers many advantages including high efficiency of energy conversion, high-power output, low cost, and high reliability. It is a superior type of E-beam systems for the radiation processing applications in the low energy region (<1MeV). The ICT power supply is the core component of the electron accelerator. The structure of the ICT cores...
In previous studies, the advantages of high temperature superconductor (HTS) DC induction heater (HIH) in energy saving and better heating quality had been provided. Compared with the conventional AC induction heater, the initial capital investment for HIH is high. The energy cost saved in the future is applied to pay the cost of HIH project. The key issue of the industrial application is to...
In this study, a wireless power transfer (WPT) technology with a superconductor was proposed. The proposed technology maximizes efficiency by applying superconducting characteristics to the resonance coil. To maximize the efficiency of the resonance coil during WPT, it is essential to consider the inductance and coupling coefficient (k). They are determined by the shape of the resonance...
Transmission integration of power and the gas could be realized If a superconducting DC cable uses liquefied natural gas (liquefaction temperature: 110K) or liquid hydrogen (liquefaction temperature: 27K) as the cooling medium. Therefore, the efficiency and reliability of the liquefied natural gas (LNG) integrated energy transfer system can be improved using superconducting DC energy transfer...
In South Korea, Korea Electrotechnology Research Institute (KERI) has developed 154 kV smart HTS cables since 2017. The smart HTS cable has a fault current limiting function. There are two types under development, resistive and inductive.
When the HTS conducting layer of a resistive smart HTS cable is quenched by a large fault current flowing to the HTS layer, the resistance of the cable...
Compared with traditional open fire heating, induction heating has the advantages of high efficiency, energy saving and environmental protection. There are two basic forms of induction heating: longitudinal flux induction heating (LFIH) and transverse flux induction heating (TFIH). The magnetic induction line produced by TFIH is perpendicular to the heated workpiece, which is suitable for...
Electromagnetic forming is a technology that employed electromagnetic force to accomplish the deformation of the metal with high conductivity. It is reported that the improved formability and reduced spring back are observed during the EMF. Combined other advantages such as good control performance and contact-less, EMF technology draw more attentions as a promising solution for the room...
In aluminium manufacturing plants typical billets having 200 mm diameter and 1000 mm height are pre-heated to a temperature of 723.15–773.15 K in order to soften the metal before it is pressed through the extruder. Due to the similar physical properties of aluminium and copper the efficiency of these heaters is in the order of 50%. In order to improve the efficiency superconducting DC...
In the project construction and daily maintenance of overhead power distribution lines, it is necessary to know the actual situation of the auxiliary parts for power polses, such as chassis, chuck and puller, to prevent the poles from pulling up, sinking and lodging. But due to the inconvenient excavation of power poles or the large amount of excavation work, trenchless detection technology...
Due to low acoustic noise, low vibrations, reduced maintenance and inherent overload protection, magnetic gear (MG) has been extensively used in many industrial applications for transmitting torques and adjusting speeds. However, the biggest shortcoming of MGs is their poor torque densities. Although several attempts have been conducted for improving their torque density, such as optimizing...
Compared with mechanical gear, Magnetic gear has the advantage of low acoustic noise, low vibrations, reduced maintenance and inherent overload protection. Although magnetic gears have many merits, the utilization of PMs and torque density of magnetic gears are extremely low due to the influence of parallel-axis topologies. In recent years, coaxial magnetic gear (CMG) has been put forward, and...
In the construction of distribution transmission network, in order to check whether the poles and towers are built as required, it is necessary to detect the underground tower base which is made up of concrete-filled steel tubular. The transient electromagnetic method can obtain location information of underground metals when they induced secondary induced voltage on receiving coil caused by...
The plasma confinement of the International Tokamak Experimental Rector (ITER) is provided by the magnetic field generated by 18 toroidal field (TF) coils while 6 poloidal field (PF) coils have the function to shape and pre-heat the plasma. Fusion for Energy (F4E), the European Domestic Agency for ITER, is responsible for the supply of 10 TFC and 5 PFC to the ITER project. The ITER...
The DDT (Divertor Tokamak Test) machine is under construction at the Frascati research center of ENEA and is aimed to investigate the possible divertor solutions for the management of power and particles exhaust for the EU-DEMO tokamak. Its Poloidal Field coil system is constituted by 6 magnets, identical in pairs as the machine is foreseen to be fully symmetric to allow for plasma...
The Divertor Tokamak Test facility (DTT) is an experimental tokamak machine to be built in Frascati, Italy, at the ENEA research centre. During its development, the DTT has gone through several important design updates. Developing a rigorous finite element methodology to evaluate the performance of all its components has thus been a critical part of the verification phase of each new design...
In the EU DEMO fusion reactor, currently in its pre-conceptual design phase, the long plasma pulse duration and the large thermal loads represent a challenge for the power exhaust, so that a new, robust design of the divertor is needed. For this reason, several DEMO-relevant divertor solutions will be tested in the Divertor Tokamak Test (DTT) facility that will be built in Italy. It will be a...
In the context of the European Fusion Roadmap, the Divertor Tokamak Test (DTT) experimental reactor is intended to investigate alternative divertor configurations in view of the EU-DEMO power exhaust handling necessities, and it is to be built at the Frascati ENEA research centre in Italy. The six poloidal field coils of the tokamak are responsible for the plasma shape and equilibrium, and...
The “Divertor Tokamak Test” facility, DTT, is a project of an experimental tokamak reactor developed in Italy, in the framework of the European Fusion Roadmap.
This work presents the magnetic and the structural assessment of the performance of the DTT central solenoid.
The CS is the core magnet of the poloidal system and generates the magnetic flux needed to induce the plasma current....
In the framework of EU design activities for dimensioning the future fusion DEMOnstration reactor (DEMO), extensive analyses were conducted in EUROfusion context, aiming at ultimately defining the design of the DEMO magnets system. In this objective CEA proposes design for all cryomagnetic systems: Toroidal Field (TF) coils, Central Solenoid (CS) and Poloidal Field (PF) coils.
In the last...
The design of DEMO PF coils is proposed and analysed based on the requirements defined by the EUROfusion 2019 DEMO baseline. Two types of forced flow cable-in-conduit conductors are used: NbTi with high void fraction and Nb3Sn with a dedicated cooling channel. The design addresses the dimensioning of the winding pack, the electromagnetic field calculations, stress analysis and thermal...
The Swiss Plasma Center (SPC) has developed a layout of Toroidal Field (TF) coil for EUROfusion DEMO tokamak, basing on a reference baseline of 2015. Each TF coil winding pack is wound with graded Nb3Sn conductors and consists of 12 single layers, connected in series by means of inter-layer joints.
The design of inter-layer joints takes into account the react-and-wind (R&W) manufacturing...
State-of-the-art high field solenoids make use of hybrid designs exploiting the superior high field performance of High Temperature Superconductors (HTS) in the innermost region. The benefits of a hybrid Central Solenoid in a pulsed tokamak like DEMO can be two-fold: either to reduce its outer radius (which would result in a reduced overall size and cost of the tokamak), or to increase the...
Second-generation high temperature superconductors (HTS) are available for producing >25 T at magnet bore compared to 16 T for low temperature superconductors (LTS) magnets proposed in recent studies of the Fusion Nuclear Science Facility (FNSF), thus enabling higher fusion power density and a smaller device size. High current density is required for engineering design of the next step FNSF to...
The goal of the Gas-Dynamic Multimirror Trap (GDMT) project is to create a multi-functional experimental facility and lay the groundwork for future development of fusion applications of open-ended magnetic plasma confinement systems with linear axisymmetric configuration. Among the most promising plasma confinement concepts to be studied on this facility are the diamagnetic plasma confinement...
The conceptual design for the superconducting coils of the K-DEMO tokamak has been proposed and continues to be updated. The toroidal field coils rely on Nb3Sn technology with new generation high Jc strand. The design is that of a cable-in-conduit conductor (CICC) consisting of multistage Nb3Sn cable inside a rectangular stainless steel jacket. There are huge Lorentz forces on the cable due...
Conceptual design studies of the helical fusion reactor FFHR-d1 are progressing at National Institute for Fusion Science (NIFS) for realizing steady-state fusion energy production. The continuously wound helical coils have the major radius R of 15.6 m, four times that of the presently working Large Helical Device (LHD) with R = 3.9 m. The High-Temperature Superconducting (HTS)...
The FFHR Design Team has been investigating several types of High-Temperature Superconducting (HTS) large-current capacity conductors to be applied to the LHD-type helical fusion reactor FFHR-d1 (major radius R = 15.6 m). Presently, before realizing this commercial fusion reactor for electricity production, smaller reactors FFHR-c1 (R = 10.92 m) for DEMO and b1 for volumetric neutron source...
In this article, we presented a technical design of the superconducting Dipole magnet, H-type like the SAMURAI magnet at RIKEN, for the Lithium(Li) alloy, the material of first wall of ITER Demo, magnetofluid behaver study, depending on mechanics, thermal and electromagnetic multi-field couple analyze results. Each coil has 1998 turns, with the inner diameter was 1.5m. The wire has NbTi...
JT-60SA is a fusion experiment tokamak device using superconducting magnets to be built in Japan. This joint international project involves Japan and Europe. In this work, we presents the design of cryodistribution and its components which are composed of a main transfer line (TL) and valve boxes (VB).
Five coolant loops are distributed between a helium refrigerator system (HRS) and cold...
JT-60SA is one of the experimental nuclear fusion reactors with superconducting magnets. It is a joint international research and development project involving Japan and Europe. The transitional change of temperature distribution of these magnets in recovery from the coil quench is investigated.
The quench recovery period is necessary to be confirmed. Generally, the maximum temperature drop...
EAST (Experimental Advanced Superconducting Tokamak) has been carried out fourteenth campaigns since its implementation at the end of 2005. The cryogenic system is one important subsystem which is to cool down the superconducting magnets and relating components. Alarm and interlock system ensure the reliability and safety of cryogenic system. This paper presents the overview of the alarm and...
With the development of superconductivity technology, more and more large scale superconducting coils or magnets are used in the scientific installation like tokomaks, particle accelerators and colliders. Before installation, each coil is needed to cold test at nominal operating current to minimize the risk of malfunction. Hence, a helium refrigerator with an equivalent cooling capacity of 5...
A proton therapy facility with multiple treatment rooms based on superconducting cyclotron scheme is under development in HUST (Huazhong University of Science and Technology). This paper will introduce design and development of the beamline system that convers the ESS (Energy Selection System) section based on an energy degrader, the gantry beamline with image optics, and a kicker system which...
We proposed the air-core cyclotron using high-temperature superconducting (HTS) technology, named Skeleton Cyclotron, as high intensity compact cyclotron. Skeleton Cyclotron consists of split main coils generating the isochronous field and sector coils generating the azimuthally varying field (AVF). Rapidness and reproducibility of magnetic field change for various particle and various energy...
A new proton therapy facility is under development in Huazhong University of Science and Technology.Scanning magnets play an important part in this facility, which affect the size of the radiation field by controlling the trajectory of the proton beam.Two independent dipole magnets, magnet X and magnet Y, scan the beam in horizontal and vertical, respectively.In order to reduce the temperature...
The scanning magnets in the proton therapy nozzle control the deflection of the proton beam by changing the magnetic field, so that the position of the proton beam can be controlled precisely, within 0.5mm error at lateral and longitudinal position. In order to meet the requirements for precise control of the beam position, a multiple redundant adaptive PID control system for scanning magnets...
A rotating gantry enables charged particles to be delivered to a tumor with great accuracy in heavy particle therapy. Hence, cancer therapy that does not damage a patient can be realized with a rotating gantry. The world’s first rotating gantry composed of superconducting magnets was developed in the National Institutes for Quantum and Radiological Science and Technology in 2015. Using...
In this study, a novel cancer treatment with low side effect and less invasiveness by blocking newborn blood vessels around the diseased part was proposed. In the therapy, ferromagnetic particles administered into the body are accumulated in the newborn blood vessels using a rotating magnetic field, and then are aggregated by a uniform magnetic field to block the blood vessels. The blockage...
Repetitive Transcranial Magnetic Stimulation (rTMS) is a non-invasive biological stimulation technology. For ideal therapeutic effect, the stimulation current usually has a rather high amplitude. Since the resistance of stimulation coil can’t be neglected, large Joule heat will be generated during treatment. Once the coil temperature is beyond safety margin, the stimulator will be suspended,...
Since the rotor is supported by mechanical bearings, the mechanical friction and wear exist in the conventional wind turbine inevitably, which not only increase the starting wind speed and the maintenance cost, but also reduce the efficiency of power generation and the operation stability. In order to overcome these disadvantages, a magnetic suspension wind turbine (MSWT) is proposed....
A high-speed permanent magnet synchronous generator (PMSG) has been applied to a variety of industries due to its many advantages, as simple structure and high output density. However, since the required speed of the rotor is increased, the structure problem of the rotating machine is continuously caused due to the physical contact in the case of the conventional ball bearing.
In this study,...
Owing to their many advantages, such as high efficiency, high power density, simple mechanical construction, no excitation loss, and good reliability, high-speed permanent magnet synchronous generators (PMSGs) are gaining considerable attention from academia as well as industry worldwide. Because of the high-magnitude centrifugal forces that are exerted on the permanent magnets (PMs) in...
For permanent magnet (PM) linear generators to be applied to ocean wave energy converters, highly efficient energy conversion is important; however, for maximum power generation, wave motion variation must be treated in real time. Therefore, we propose a characteristic map of the generating performance, including characteristic results of power, losses, efficiency, force, and the power...
Recently, with the emergence of several global industries, linear oscillating actuators (LOAs) have been developed for various applications where short-stroke linear motion is required. In common LOAs, since electromagnetic losses are the parameters that determine the operating conditions and efficiency of most electrical machines, it is very important to accurately predict and reduce these...
With the power increasement of permanent magnet (PM) machines, the manufacture process and maintenance of irreversible demagnetization become increasingly difficult, which limits the magnetic field configuration design of large PM machines. Post-assembly magnetization method is the key to solve these problems and can improve the machine performance. One way is adding additional integrated...
The single-phase linear permanent magnet generator (SPLPMG), which is applied to the free piston Stirling engine (FPSE), has a simple structure and robust topology.
When a linear drive system such as a free piston Stirling engine is applied, a linear generator does not require a mechanical energy conversion device such as a screw or a crankshaft, and thus has a small mechanical loss and a...
Recently, eco-friendly vehicles such as pure electric vehicles (EVs), hybrid EVs and plug-in hybrid EVs (PHEVs) have been the subject of many studies in a dramatically accelerated effort to increase the total driving distance on a single charge. Among of PHEV components, increasing the efficiency of the engine generator system (EGS) is a key challenge in this effort. In the EGS, a generator...
A novel single phase tubular permanent magnet linear generator for Stirling engines is proposed in this paper. It has a bread type winding, which has no cutting. It comprises an outer-stator, an inner-stator and a mover, and they are mounted in a cylinder. The winding coils are wound in a ring shape and placed in the slot of the outer-stator. The inner-stator is made up of a ferromagnetic...
Rotational machine is a kind of promising high temperature superconducting (HTS) electrical application. Among them, the coated conductor HTS coils are most commonly used as DC magnets because the DC HTS coils in the rotor under the relatively stationary fundamental magnetic field does not cause AC loss. However, in actual operation, AC loss produced by the harmonic magnetic fields is...
In this paper, the motor-generator set was developed to test the various output performance of a 1-kW-class high-temperature superconducting generator (HTSG) which is charged by HTS contactless rotary excitation device (CRED). First of all, the various full components for 1-kW-class HTSG were manufactured and assembled including a salient rotor pole with HTS coils, rotating shafts, torque...
This paper focuses on the design of a Vernier machine with HTS bulks on Flux Modulation Pole(FMP) and HTS field winding. Vernier machine gained importance in recent years for low-speed and large- torque (LSLT) applications, such as wind power generation. Despite the Low-speed high-torque capability, Vernier machine have lower Power factor than the power factor of conventional HTS Field Winding...
China Southern Power Grid, Ltd. has established a project to study the feasibility of installing large-scale HTS dynamic synchronous condensers in Ultra High Voltage Direct Current (UHVDC) transmission grid. To investigate some key technologies, a small–scale one, such as 300-kvar class HTS synchronous condenser prototype is designed. The electromagnetic and structure design of this prototype...
Nowadays, feasibility study of fully turboelectric propulsion systems for electric aircrafts are being conducted. Fully superconducting rotating machine is one of the solutions to realize fully turboelectric propulsion systems with lightweight and high power density. In our previous studies, we reported the high output power density over 20 kW/kg for the 10-MW-class fully superconducting...
This paper presents the results of the electromagnetic design and numerical analysis for a 10-MW-Class second generation high-temperature superconducting generator (2G HTSG). Since the offshore wind power has the technical and economic difficulties in a regular maintenance due to geographical conditions that are difficult to access, the operation reliability of 2G HTS coil for the rotor-field...
A unique activation technique for permanent Nd-Fe-B magnets which were embedded in the rotors of interior permanent magnet (IPM) motors has been developed as a magnetizing tool using high temperature superconducting (HTS) bulk magnets. The experimental and numerical simulation studies were conducted to evaluate the magnetic field-trapping performances in two manners of we call “scanning” and...
Magnetization of RE-123 coated conductor influences the spatial homogeneity and time variation of the magnetic field of a magnet. This has been an important issue for the realization of MRI, NMR and accelerator comprising the coated conductor. Therefore, the measurement and modelling of the magnetization of the coated conductor is crucial for the quantitative estimation of its influence on a...
We study to increase a trapped magnetic field of HTS bulk magnet activated by pulsed field magnetization (PFM). Although various methods to enhance the trapped field are considered, they can be broadly divided into two approaches; one is improvement of magnetizing method and another is modification of exciting equipment. In the latter, a pulse width was expanded by changing an inductance of...
We have studied both theoretically and experimentally the process of magnetization of HTSC square (12mm x12mm) tape as well as stack from tapes by means of small source of magnetic field. The size of magnetic field localization was less than the size of sample. Local magnetic field induced the currents which were calculated in the frame of critical state model taking into account the...
The field and field quality was modeled for a DC planar undulator designed to be wound with YBCO coated conductor. The undulator field on axis target was 1.3 T with a period length of 17 mm. The winding former and pole material were 1006 LCS, and the gap was 9.5 mm. A tape wound design was used, with 50 tape layers in a groove. The tape was taken to be 4 mm wide and 0.08 mm thick, with 10 m...
Due to its excellent current-limiting capacity, especially at the initial dc fault transient stage, the analyses of dc inductive superconducting fault current limiter (I-SFCL) are attracting more attention. In this paper, a modelling method for dc I-SFCL was proposed to describe its nonlinear characteristic of inductance. Firstly, the structure of dc I-SFCL was briefly introduced. Then the...
Abstract: The short-circuit fault current on the DC side affects the operation safety of the multi-terminal flexible HVDC transmission system (MTDC) seriously. At the same time the superconducting fault current limiter (SFCL) has received extensive attention in limiting the DC impact current due to its characteristics such as fast response speed, good current limiting effect and zero impedance...
In a power system, fault currents are on the rise and are becoming a common problem. Although several methods are used to restrict fault currents, the methods have demerits in respect of stability and reliability of power system. In this regard, high temperature superconducting (HTS) fault current limiting applications are considering as an alternative and a number of related researches are in...
The level of fault current has been increases quickly with rapid growth of electric load in recent years. The capacity of conventional circuit breaker has been unable to meet the demand. The wide application of high temperature superconducting fault current limiters (HT SFCL) provides a new avenue for power protection. They use the electrical properties of HTS to instantaneously protect power...
Recently, high voltage direct current (HVDC) power systems have been widely developed and used around the world because of their large transmission capacity and low power loss. However, conventional DC circuit breaker (DCCB) is difficult to interrupt large fault current. Therefore, to limit the fault current to a relatively low level, a superconducting fault current limiter (SFCL) is...
Fault current limiter (FCL) is commonly applied as a current-limiting device to improve the stability of the power system. In this paper, a Flux-coupling type Superconducting FCL (FC-SFCL) with a pair of HTS parallel windings has been developed. The limiter is based on disconnecting coupling windings for current-limiting, which has a low steady impedance at normal state and higher limiting one...
The flux-coupling-type superconducting fault current limiter (FC-SFCL) has been proposed to solve excessive short-circuit current in power system. FC-SFCL promotes the breaking capability by connecting two circuit breakers in parallel through two high-coupling coils. Since each coil is made of multiple coil units in parallel, there may be a problem of unbalanced current distribution, resulting...
System operators make an effort to solve the fault current problem due to increase of distributed generation and complexity with parallel connection of the power system. Announced methods for solving the fault current such as replacing circuit breaker, installing high-impedance power equipment or series reactors have problems with cost, voltage drop, and power loss. The SFCL (Superconducting...
The yttrium-barium-copper-oxide (YBCO) coated conductor, which supplement the fault of the existing superconducting current-limit materials YBCO thin film, bismuth-strontium-calcium-copper-oxide(BSCCO) wire and bulk, has been improved its mechanical weakness and has high index; hence, after quench YBCO coated conductor could limit the fault current effectively because of fast resistance...
For the application of superconducting wires to fault current limiting devices, it is required that they have a high rated voltage when a fault occurs. Stabilizer-free coated conductors, particularly, shows a good performance for the high rated voltage, which is beyond 0.6 V/cm. In this study, using the stabilizer-free coated conductors, we made fault current limiting devices and examined...
We investigate the comparison of fault current characteristics between the separates three-phase flux-lock type superconducting fault current limiter(SFCL) and integrated three-phase flux-lock type superconducting fault current limiter(SFCL). The single-phase flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil on an iron core and...
The paper presents the design and test results of a conduction cooled flux coupling type superconducting fault current limiter. The 6 kV / 140 A SFCL was tested with a 2500 MVA short-circuit generator at a high power test facility. The design of the limiter consists of two parallelly connected and magnetically coupled windings cooled by single stage cryocooler. Magnetically compensated...
With the development of integrated power system (IPS) applications in navy, medium voltage direct current (MVDC) for shipboard electrical distribution is widely focused on. Compared with medium voltage alternating current (MVAC), MVDC is more adequate and affordable to meet electrical demand of future destroyer. However, one of the bottlenecks restricting the development of MVDC in shipboard...
The level of short circuit current in power system is increasing rapidly, flux-coupling superconducting fault current limiter based on paralleled superconducting windings can effectively limit short-circuit current by the increased impedance after decoupling of the windings. The superconducting windings of high coupling factor is the core component of this SFCL, and the voltage distribution of...
The resistive superconducting fault current limiter (RSFCL) is widely used in high voltage direct current transmission based on modular multilevel converter (MMC-HVDC) to effectively limit the fault current and facilitate the interruption of the DC circuit breaker. During current limiting process, the RSFCL needs to withstand an overcurrent impact with a magnitude of several times the critical...
With the development of DC power supply systems, breaking capacity of circuit breakers has been increasingly unable to meet the growing requirements for DC system short-circuit current level. To ensure the safety of the systems, a fault current limiter must be used in series with circuit breakers. The properties of superconducting fault current limiters such as fast reaction rate, simple...
With the development of modern power systems, the generation of fault currents and the system sensitivity to fault currents have increased. A superconducting fault current limiter (SFCL) is emerging as an alternative to reducing such fault currents in alternating current (AC) and direct current (DC) systems. SFCL can perform faster current limit operation as well as automatic fault current...
In recent years, power devices using direct current are increasing rapidly. Especially, the development of renewable energy including photovoltaic power generation has led to the expansion of direct current (DC) power generation sources, so that interest in DC systems is increasing. However, the obstacle in the DC system is that dc circuit breaker (DCCB) is still under development. In this...
To efficiently protect a high voltage direct current (HVDC) system containing line commutated converter (LCC) and voltage source converter (VSC), this study proposes to coordinate resistive superconducting fault current limiters (SFCLs) and hybrid DC circuit breakers (HDCBs) to clear the DC line fault. The principle modeling of the resistive SFCLs is stated, and the impacts of the SFCLs on the...
In order to effectively solve the low-voltage ride-through (LVRT) issue of a virtual synchronous generator (VSG) under severe grid fault, this paper proposes and studies the application of a flux-coupling-type superconducting fault current limiter (SFCL). Since the magnetic flux of the SFCL has a high controllability and its current path can be flexibly adjusted to cause the quench of high...
Fault current is one of the basic threats to the elements of power systems. Fault current in a shorted circuit is usually many times greater than the current occurring during normal operation of the network equipment. Fault current flow can cause thermal and dynamic harmful effects on the operation of power equipment. Electrodynamic forces occurring during the fault current flow can...
In order to optimize the structure design of CFETR TF conductor, the influence of rectangle and square conductor on the current transport performance is demonstrated. To analyze the mechanical structure and strands damage caused by different shape, a square and a rectangular experimental conductor were designed and manufactured by ITER TF and CFETR CSMC cable design. The indentation damage and...
Madmax (MAgnetized Disc and Mirror AXion) project is an experiment dedicated to the discovery of the axion particle, the mass of which is expected in the range of 100 µeV. A square-field integral value of 100 T²m² with a 5 % homogeneity over 2 meters along the axis is required. The conductor has been designed to minimize the global magnet cost while fulfilling the following constraints: the...
The conceptual design of the superconducting magnet system for the DEMO tokamak is being carried out in Europe since a few years. The Toroidal Field (TF) coil requirements and main geometrical features have undergone a series of changes, as a consequence of iterations leading to system-level machine optimization. In particular, solutions with 16 or 18 TF coils have been investigated, operating...
The electrical performance of cable-in-conduit conductors made from Nb3Sn superconductor can degrade during operation, depending on the operating parameters selected and the cable pattern and geometry. In this study, we perform a comparative destructive examination on two identical ITER TF conductor sections, one of which is heat-treated but untested, and the second of which has been tested to...
The testing of samples of “cable in conduit conductors” (CICC) made of Nb3Sn and copper strands for ITER toroidal field coils in general cases demonstrated the degradation of current sharing temperature Tcs under cycling electromagnetic loads [1]. This is mostly because of a movement of superconducting strands under Lorentz forces inside a cable that causes the cracking of brittle Nb3Sn...
Superconducting cable is an important component of CICC conductor. The quality of the cable is the guarantee to ensure safe operation of superconducting conductor, and the key step to reduce the degeneration of superconducting conductor performance. The cables will be sustained extremely complex stress during manufacturing process, which is easily cause damage on strands and influent conductor...
The superconducting cables for magnet systems in nuclear fusion reactors usually adopt the Cable-in-Conduit conductor (CICC) concept. CICC cables are known for higher thermal stability compared to other cable designs. Selection of a suitable cable design for higher operational performance still remains a challenge. The maximum magnetic field in future fusion reactors like DEMO and CFETR may...
No-insulation (NI) high-temperature superconductor (HTS) coil which have self-protecting feature when quench have been presented for several years, HTS magnet using NI technique also have been applied, however, the quench behavior need to be calculated and analyzed. With the charging delay of our magnet satisfied, YBCO coated conductor tapes with copper cladding are used which have better...
In this paper we present quench analysis results of a Low-Temperature Superconducting (LTS) quadrupole triplet magnet system, a part of the In-flight Fragment (IF) separator of a heavy ion linear accelerator complex, named RAON, currently being constructed by the Institute of Basic Science (IBS). This magnet system is composed of three quadrupole magnets: a triplet, surrounded by iron yokes...
High-field magnet technology based on REBCO coating conductor is facing several critical challenges, one of which being quench detection and protection in various working conditions with or without strong stresses. We describe a fast turnaround experimental platform for testing quench initiation and detection of REBCO coated conductors for high field magnet applications.
It is essentially a...
This paper proposes a new lumped-circuit model that has been modified from the conventional one to demonstrate the fast electromagnetic quench propagation among electromagnetically-coupled no-insulation high temperature superconductor (HTS) coils. Recently, multiple groups have reported that the conventional lumped-circuit model, which has well demonstrated charging and discharging behaviors...
High-temperature superconducting (HTS) device is a new application of superconducting technology in the electric power network. It shows several advantages, including small volume, light weight, high efficiency, strong capability of overload, and risk-free of fire. In this paper, we designed a core cable based on the adiabatic conditions, and then realized both numerical and experimental...
When High-temperature Superconducting Coated Conductors (HTS-CCs) are subject to a transport current of the order of the critical current, their low thermal diffusivity and nonuniform critical current density can easily lead to the appearance of destructive hot spots. The transition to the normal state probably causes the degradation of superconducting properties in HTS-CCs. In recent years,...
In this study, the quench initiation and propagation characteristics of second generation high temperature superconducting race-track coil (2G HTS RTC) are investigated in both experiment and simulation. This RTC is insulated by the metal-insulator transition (MIT) insulation material which has a variability of the contact resistance as a function of temperature. First, thermal quench tests...
Abstract: Because the current carrying capacity of a single superconducting tape is limited, in some practical superconducting devices, multiple tapes need to be used in parallel. Due to the inhomogeneity of the tape and their uneven current distribution, hot spots are easily formed on some of the tapes when the superconducting device passes through large current. The normal zone will not only...
In this paper, a novel 3-phase 12/10-pole rotor-permanent magnet (PM) hybrid excited axial switched-flux (RPM-HEASF) machine is proposed and investigated, which exhibits high power/torque density, wide speed-regulation range, and good overload capability, and is interesting for electrical vehicle (EV) or hybrid EV applications.
The RPM-HEASF machine contains double-outer-stator and...
The use of a permanent magnet (PM) to achieve high performance and high efficiency in the modern motor and generator industry technology has increased rapidly. In the design process, one needs to consider the magnetic properties and the eddy current loss due to high conductivity in long term operating condition. Due to high eddy current loss the temperature of the permanent magnet increases...
To investigate the electromagnetic characterization of HTS coil under a travelling magnetic field, a no-insolation racetrack coil was wound with YBCO tapes. For comparison, another HTS coil which has the same geometric and structural parameters was wound with insolated tape between the layers. The coils were injected with DC current and a flat stator which has traditional copper windings and a...
Regarding a linear motion and forces the linear electric motors have a number of advantages over ordinary motors, the most obviously the lack of an intermediate gearbox to convert rotational motion into straight line motion saves energy. Essentially linear electric motors with conventional conductor (copper) coils are designed to produce high force at low speeds and the demand for these...
The surface-mounted permanent magnet linear motor (PMLM) is a good candidate for the application of urban transit due to its merits of high-power density and efficiency. However, this kind of machine needs a lot of permanent magnets (PMs) on the long stator structure, which is costly. To solve this problem, a novel PMLM has been proposed in this paper. The stator of novel PMLM has the...
Since only one tenth of the ore is deposited as rare earth elements, these elements are not common. However, these elements are constantly needed to be used to supplement the thermal demagnetization strength of the motor.
However, there are many cost variables and risks for continuous use of these elements, since these elements are mainly buried in only certain countries.
Recently, a lot of...
When designing a motor, the motor should be designed to withstand harsh conditions, for it to operate at any extreme environment. For the motor that uses permanent magnet (PM), its irreversible demagnetization is undesired characteristic that has negative effect on motor performance. As interior PM synchronous motor (IPMSM) is often used for high torque density generation, its operation...
Permanent magnets are largely classified into ferrite magnets, Alico magnets, and rare earth magnets. Ferrite magnets and Alico magnets are significantly less magnetic than rare earth magnets. Therefore, when a rare-earth magnet is used, it is advantageous in size and weight because it uses less magnet than other magnets. Particularly, in the case of a magnet used in a vehicle, it is necessary...
This paper describes the analysis on the Number of Axial Segments of Permanent Magnet in SPMSM for Ultra-High-Speed Application; Electric-Turbo Compound System(E-TCS) for Construction Equipment. E-TCS is a device that combines a turbocharger, which is a regenerative device through exhaust gas, and a compressor to improve the turbo lag. As a result, E-TCS must be able to drive at least 80,000...
Due to its stator robustness and the substitution of permanent magnets by DC field windings, the magnetless linear variable reluctance motor (MLVRM) possesses several advantages: high reliability, low cost and flexible flux regulation capability, which is a good candidate for rail transit applications. However, the MLVRM is essentially a doubly-salient machine, so there exists a drawback of...
Several tubular switched reluctance linear machines (TSRLMs) with transverse flux are proposed for improving thrust density recently. Owing to the particularity of the structure of transverse-flux TSRLMs, how to maximize the electrical utilization becomes a key to improve these machines’ performance. A novel three-phase transverse-flux TSRLM is proposed in this paper, whose stator sleeve is...
Synchronous electric machines with superconducting field windings have been around for a long time but have not gone beyond prototypes and very limited demonstrations. However, magnetic resonance imaging (MRI) systems use superconducting magnets that are made in significant volumes each year and run with high reliability. Leveraging significant technology advances in cryogenic systems...
A fundamental challenge with High Temperature Superconductors (HTS) is their high critical temperature (Tc) values and the stability that they impart when used in a magnet device with sufficient stored energy. Low normal propagation velocities and high stability of HTS wires cause localized damage due to an excessive peak hot spot temperature during a quench. Protection of HTS magnets for...
Compared with conventional rotary machines, linear motors have no mechanical transmission device and, therefore, offer higher transmission efficiency, lower noise and easier to maintain. Hence, they have attracted a lot of attention in urban rail transit recently. Among them, linear induction motor (LIM) merits the advantages of simple structure, and has been applied in some countries....
A high temperature superconductor tri-axial CORC cable has been designed for all electrical aircraft. This paper is to study the magnetization loss of this tri-axial cable under time-varying external magnetic field. This cable is wound with ReBCO tapes from SuNAM, Korea. An experimental platform is built to measure the magnetization loss using an electrical method. The tri-axle cable is...
This paper proposes optimizing the magnetization direction of isotropic ferrite permanent magnets (Fe-PM) to enable the maximization of back-electromotive force (B-EMF), torque density, and minimum torque ripple of surface permanent magnet brushless direct current motor. The concept design is divided into two steps. First, two general Fe-PM electric oil pump motor models with radial and...
Recently, as the demand for high-speed trains increases, studies on the stability of high-speed trains are actively under way. In the conventional case, most of the high-speed trains were driven by friction with the rails mounted on the rotating electric motor. In this case, unevenness and friction between the rail and the wheel caused the driving performance to drop, causing large vibration...
A policy that mandates the use of high-efficiency devices in order to use energy resources reasonably is being implemented. Induction motors are the most commonly used energy consuming equipment and are highly effective in high efficiency design. For the design of high efficient induction motor. satisfying the high starting torque, the double bar type bar type rotor was designed. In the case...
The design of a cylindrical linear generator involves the calculation of the stator winding as a function of the magnetic field inside the solenoid, in such a way that the generation of the voltage obtained will be a function of the number of turns and the speed of the movement of the magnetic field inside. On the other hand, the use of HTS tapes in applications of linear electrical machines...
High-temperature superconducting (HTS) machines received tremendous attention recently in the high power applications such as wind power generators and electric propulsion for ships, as they offer both high power density and high efficiency with the improving performance of HTS windings. In conventional HTS motors, HTS field windings are commonly constructed with HTS coils which supplied with...
Due to the application limitation of permanent magnet and the ever-growing market requirement on linear motional equipment, the wound field linear machines are still drawing much attention. In this paper, a novel wound field flux reversal linear machine (WFFRLM) is proposed, which has both excitation windings and armature windings on a dual-side primary core, offering high thrust density and...
Motivated by growing needs for high speed transportation system, Korea Railroad Research Institute (KRRI) has developed the core technology of HTX (HyperTube eXpress) that operates vacuum tube above 1000 km/h. In order to achieve subsonic speed and dynamic stability, efficient propulsion and levitation systems are required, and consequently the subsonic capsule train has been developed by the...
The induction motor(IM) is used in a variety of fields such as home appliances and factories, automobiles and railroad cars. Therefore, each motor has different target performance and the shape of the rotor is different. Use a cage rotor(CR) when the efficiency of the IM is important, and a double cage rotor(DCR) when starting torque is important. Starting torque and efficiency are in a...
Linear synchronous motor is expected to be widely used in pulse power application, such as electromagnetic launch. A High Temperature Superconducting linear synchronous motor (HTS-LSM) for pulse power application is developed in this paper. A HTS winding is used as the moving coil, the stator coil is wound with copper winding. The superconducting winding has been excitation to flow DC current...
The “Bitter” magnet has been serving high field science community over decades, since its first implementation by MIT in the 1930s and its variation of the Florida Bitter by the National High Magnetic Field Laboratory in the 1990s. With a proper water-cooling environment, average current density of such a bitter magnet reaches ~600 A/mm^2 with a field generation capacity of >40 T. This paper...
We report on the results of magnetic measurements, in particular, of the first short models of twin-aperture magnets for the CERN Future Circular Collider (FCC-ee) arcs. To date, we have built and tested three 1-m long bending magnets, using different materials for the ferromagnetic yoke and a 1-turn vs. multi-turn excitation. Besides the interest in checking the unusual I-layout, the focus is...
High temperature superconductors, such as YBCO, are being considered for high magnetic field magnets to be used in particle accelerators. A knowledge of the magnetic properties of these superconductors, and in particular the cables made from them are needed for accelerator magnet design. Here we present measurements of HTS CORC and Roebel cables using two devices. First, from a hall probe rig...
Flux pump field magnets have the ability to generate high fields through avoiding utilizing current expensive high-current power supplies and warm-to-cold current leads. The resultant effect is that the purchase and running costs of high-field magnets will decrease substantially. Thus it is realistic to expect HTS flux pumped magnets to be available which could be installed widely enabling a...
The Main Beam Quadrupole (MBQ) magnets of CLIC, the Compact Linear Collider under study at CERN Laboratory in Geneva, are part of a critical magnet family, considering the industrial production challenges. An R&D program on the MBQ magnets was launched for studying and investigating several assembly solutions in order to minimize the procurement cost of a large series of magnets comprising...
This report details the design of and results from a fast-switching, high power density HTS switch. The switch design initially used commercially available second generation HTS tapes, with later prototypes using thin films of YBCO on sapphire. The method used to switch into the off-state is through application of an AC magnetic field to the superconductor, causing any transport current to...
A new horizontal shift bump electromagnet for the J-PARC RCS injection bump system was designed and fabricated. The magnet is a pulse magnet that repeatedly excites a trapezoidal waveform of about 1.5 ms at 25 Hz. And it is possible to change of the rising and falling time of the pulse waveform with the maximum current of 16 kA and the voltage of 12 kV between 150 and 500 microseconds...
Striation is one of the approaches to reduce the shielding-current-induced fields (SCIFs) in magnets wound with coated conductors. We focus striated and copper-plated coated conductors, in which the current sharing between filaments through plated copper could improve their stability and could help their quench protection. It should be noted that the striation is effective to reduce SCIF only...
Aiming to demonstrate the feasibility of a 10-kA class all-ReBCO based superconducting rectifier of the transformer-type, the development of high current ReBCO switches is crucial. A group of four switches in a bridge arrangement called switch-bridge has been developed. The switches are based on cyclic thermal heating of stacks of ReBCO tapes, operating in the 50 to 60 K temperature range when...
Production-quality magnetic measurements are required to characterize accelerator magnets for the Advanced Light Source Upgrade (ALS-U). Measurements of the magnetic axis, multipolar content and mechanical fiducialization are typically performed on three separate apparati. In this work, we describe the methodology and development of a combined-function, stretched-wire magnetic measurement...
A straight forward solution to reduce the heat load of Current Leads to superconducting magnets operating at 4 K is the use of high temperature superconductors (HTS) thereby eliminating the ohmic heating at the 50-77 K range. The heat input from the current leads is then determined by heat conduction in the HTS section only, leading to some factor 10 reduction in the heat load in comparison to...
TRIUMF is constructing a new facility, ARIEL, for rare isotope beam (RIB) production using the ISOL method. ARIEL will increase the production and enable the delivery of three simultaneous radioactive beams, making it the first multi-user RIB facility worldwide. The selection of such beams will be achieved by means of a new high resolution mass separator system, funded though the CANREB...
Future circular accelerators for high-energy particle physics are expected to rely on increasingly higher magnetic fields for steering and focusing the particle beams. High temperature superconductors (HTS) are a promising technology for such future accelerator magnets. In particular, superconducting tapes based on rare-earth cuprate compounds (ReBCO) are potentially excellent candidates. Such...
The Future Circular Collider (FCC) electron-positron version may be the next step towards a next generation of particle colliders. It may include an Experiment for probing ee+ collisions using the IDEA (International Detector for Electron positron Accelerator), or similar, detector requiring a solenoid enclosing the inner tracking detector. An innovative 2 T superconducting solenoid with 4 m...
In recent years, the H-formulation of Maxwell’s equation has become the de facto standard for simulating the time-dependent electromagnetic behavior of superconducting applications with commercial software. However, there are several situations where the H-formulation is not the most suitable tool. These include for example: i) situations where the superconductor is better described by the...
In superconducting undulators (SCUs) that are currently operating at the Advanced Photon Source, the undulator magnets are indirectly cooled with liquid helium penetrating through channels in the magnet cores. The liquid helium is stored in a tank which is cooled by cryocoolers. However, a cryogen-free version of a superconducting undulator in which the undulator magnets are conduction-cooled,...
The wide range of tensile strength values (1000-1700 MPa) simultaneously with the electrical conductivity of 55-75% of the international standard for annealed copper (IACS) are required for commercial Cu-Nb wires. For the industrial production, the optimal combination of physical properties must be supplemented with the reasonable cost. One of the ways to reduce the price of products can be...
The fatigue behavior of the Zylon fiber reinforced epoxy matrix composite (Zylon/epoxy composite) has been tested under quasi-static tensile and tensile fatigue loads. The distribution of the fatigue life at different stress levels were determined. The results show that the statistical characteristic of the static strength and the fatigue life can be satisfactorily described by the normal,...
High strength and conductivity CuAg micro-composites were fabricated via casting and accumulative bundling and drawing (ADB) process. CuAg with large cross-section exhibits competitive strength and conductivity properties for pulsed magnets use. The CuAg filaments and eutectic whiskers evolution during the compositing process was investigated. The tensile properties and thermal compression...
Large structural forgings of complex shape are required for several components of the precompression structure of the ITER Central Solenoid, consisting of a stack of six electrically independent modules and featuring a total height of 18 m and a diameter of over 4 m. The precompression structure allows the vertical tensile loads to be reacted and adequate preload to be maintained, in order to...
In the framework of the FP7 EuCARD2 project, CEA Saclay developed a cos-theta insert magnet, wound with REBCO high temperature superconductor Roebel cable. Each dipole coil consists of a single arched layer of conductors, insulated with a glass fiber sleeve and impregnated with epoxy resin for mechanical reinforcement. Tooling has been developed to carefully guide the Roebel cable during the...
This paper numerically and experimentally studies the mechanical properties of quasi-isotropic strands under bending load at 77 K. Due to quasi-isotropic superconducting core fabricated by 2G wires existing in strand, bending on strand in different directions will lead to various critical current degradation, which will necessary meet during the winding of them into high current cable. Trough...
The Rare Isotope Science Project (RISP) of Institute for Basic Science (IBS) has been constructing a heavy ion accelerator complex, named Rare isotope Accelerator complex for ON-line experiments (RAON). To produce various high-intensity rare isotope beams, the RISP equips RAON with two rare isotope beam production systems: in-flight fragment (IF) separator; and isotope separator on-line...
IHEP (The Institute of High Energy Physics, Chinese Academy of Sciences) is pursuing the pre-study of SPPC, a super Proton-Proton collider prorosed to be built in the future. To reach the 70 TeV or higher center of mass energy in proton collisions, dipole magnets with 12-T or higher bore field are required. A subscale magnet named LPF1 was fabricated and tested in 2018, which reached a main...
A prototype REBa2Cu3Oy (REBCO) sextupole magnet was designed and fabricated for the chromaticity correction of an asymmetric–energy collider, named SuperKEKB. The REBCO sextupole magnet consists of six two-layer-rectangular coils, which are wound with a 4-mm-wide coated conductor and impregnated with epoxy resin. The inner bore radius and magnet length are 75 mm and 200 mm, respectively. The...
A future accelerator facility to open up a new frontier will require a superconducting magnet with high radiation resistance. A construction plan of a second materials and life science experimental facility is proposed as one of the future plans of J-PARC. At the facility, superconducting solenoids are placed just behind the target to maximize the production of secondary particles. The...
The new high temperature superconducting (HTS) quadrupole magnet with circular coils was designed and built at Fermilab. There were investigated also several HTS coils at the liquid nitrogen temperature. The main goal of this activity is to investigate coils, and the magnet operation in a persistent current mode to reduce accelerator magnets capital and operational expenses. For that was used...
An air-core HTS quadruple magnet has many advantages by eliminating iron-core of an iron-core quadruple magnet. Study on air-core HTS quadruple magnet for accelerator application is currently ongoing at Applied Superconductivity Laboratory, Yonsei University. It is comprised of 8 metal-insulation double-pancake racetrack coils, each wound with 4 mm wide REBCO tapes. An REBCO tape is of high...
A quadruple magnet, one of the superconducting magnets in accelerator system, is used to focusing accelerated beam particles. Recently developed high-temperature superconductor(HTS) has characteristics of high critical temperature and operating current densities under high-field region. Therefore, developments of HTS quadruple magnets applied to the hot cell region that has a high heat load in...
The RAON of Rare Isotope Science Project (RISP) in Korea will provide not only rare isotope (RI) beams, but also stable heavy ions, ranging from protons to Uranium. Both of the In-flight Fragment (IF) separation and the isotope separation on-line (ISOL) will be used in RAON. Six HTS quadrupole magnets and One HTS sextupole magnet will be installed in the forepart of IF separator considering...
A 3-T MgB$_2$ dipole magnet has been designed aiming at applications of compact accelerators and rotating gantries for heavy-ion radiotherapy facilities. The dipole magnet contains two identical racetrack coils. Each coil is wound by 156-m long commercial MgB$_2$ wire, with the length of the straight side, the winding diameter of the round portion and the height of 60 mm, 40 mm and 23 mm,...
ReBCO is the second generation of high temperature superconducting (HTS) materials with potential for high-field applications and low mass quality applications. The fabrication process and performance of superconducting cables are a key issue for superconducting magnets operating at high-field or large sizes. This study describes a process of a soldered stacked conductor using a 4 mm wide...
Abstract— Electron Ion Collider (EIC) will be a next generation collider to address outstanding puzzles in modern nuclear physics, supported by both Brookhaven National Laboratory (BNL) and Jefferson Laboratory (JLab). The design of the interaction region (IR) requires a high field quadrupole for the heavier proton beams and an almost field free path (desired magnetic field within a few mT)...
A hybrid-type cryogenic permanent-magnet undulator (CPMU) with a 15-mm period length is being constructed for the TPS Phase-II beamline. A control system for CPMU called CU15 which is developed since 2018. The control system for CU15 is based on the Experimental Physics and Industrial Control System (EPICS) architecture and Ethernet Control Automation Technology (EtherCAT) framework. The main...
In the phase-II beamlines project of the Taiwan Photon Source (TPS), the insertion device (ID) of elliptically polarized undulator (EPU) called EPU66 and EPU168 will be installed in 2020. The new control system for EPU is based on the Experimental Physics and Industrial Control System (EPICS), and Ethernet Control Automation Technology (EtherCAT) framework. The EPU control elements include:...
ALS-U is an ongoing upgrade of the Advance Light Source (ALS) at Lawrence Berkeley National Lab (LBL). The upgraded ring of the ALS will use a multibend-archomat (MBA) lattice, which will allow increasing the brightness of soft x-ray sources 100-1000 times with respect to current ALS capabilities. One of the goals of the project is maintaining ALS capability of producing hard x-ray beams,...
Abstract: Forty planar superconducting undulators (SCUs) with 4 m long magnetic structure will be used in Shanghai High Repetition rate XFEL and Extreme Light (SHINE). As the longest SCUs being developed in the world, they can produce the photons with energy of 10 keV – 25 keV. NbTi/Cu wire with the diameter of 0.6 mm and the ratio of Cu to NbTi 0.9 is adopted to fabricate the superconducting...
NbTi superconducting undulators (SCUs) are currently reliably operating at the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). These devices significantly enhanced x-ray flux and brightness at high energy spectrum. As NbTi SCU technology is close to its full potential, further performance enhancement requires using different superconducting materials. Nb3Sn is a promising...
Short period undulators are an essential component of compact free electron lasers (FEL) and medium energy storage rings for the production of hard X-rays. The use of ReBCO high temperature superconductors (HTS) in a staggered array undulator geometry is expected to yield a magnetic undulator field above 2T for a 10mm period and a 4mm magnetic gap, thus substantially increasing the performance...
Udulators are important insertion devices for synchrotron radiation light source such as storage ring and free electron laser facility. Comparing with undulators based on permanent magnet, superconducting undulators may maintain high magnetic fields with a shorter period length. Superconducting undulators based on NbTi coil were successfully developed and are now in operation. Recently,...
It is well understood that HTS conductors have low quench propagation velocities due to the high conductor specific heat with increased temperature. An HTS conductor with very little copper has a low value of the integral of j2dt between the magnet operating temperature and 300 K. Adding copper to an HTS conductor reduces the quench velocity within the coil and it makes the coil thicker, but...
A 3m long In-Vacuum Undulator (IVU) is employed at the National Synchrotron Light Source II (NSLS-II) for the Hard X-ray Nanoprobe (HXN) beamline providing structural and X-ray fluorescence imaging with world-leading spatial resolution. On July 1st 2018 a gearbox shaft in the gap drivetrain assembly sheared due to stress caused by mechanical misalignment. The device was extracted from the...
A PrFeB-based cryogenic permanent magnet undulator (CPMU) is under construction at the
Taiwan Photon Source (TPS) to provide high brilliant X-rays for phase II beamlines. The in-vacuum Hall probe measurement system is improved to measure and tune the magnetic field at cryogenic temperature. To ensure the measurement is taken in the magnetic field center, we also develop two methods:...
A 3D thermo-magneto-mechanical study of a variable gap, 14 mm - 10 period superconducting undulator has been conducted based on a preliminary magnetic design carried out in RADIA. The choice of the conductor is made on the basis of a safe operating margin of the superconducting winding. This margin is determined via a coupled thermal, magnetic and mechanical analysis. Thus, the studies include...
Cyclic behavior of Wendelstein 7-X magnet system during first two phases of operation
V. Bykov, J. Zhu, A. Carls, B. Hein, K. Risse, P. van Eeten, H-S. Bosch,
L. Wegener and the W7-X Team
Max-Planck-Institut für Plasmaphysik, EURATOM Association
Teilinstitut Greifswald, Wendelsteinstr. 1, D-17491 Greifswald, Germany
The sophisticated large magnet system of Wendelstein 7-X (W7-X)...
According to the Primakoff effect, axions and axion-like particles can transform into photons in the presence of a strong magnetic field. To continue the search for these hypothetical particles, a new helioscope called the International Axions Observatory IAXO, and its subscale fully functional demonstrator BabyIAXO, are being designed.
To increase the sensitivity by a factor of a 100...
The new Nb3Sn superconducting magnet system for the fourth-generation 45 GHz ECR source is under developing in the institute of Modern Physics(IMP). A mirror structure of the Nb3Sn sextupole testing coil based on a key and bladder technology is used for studying the coil's mechanical, thermal and quench performance under the realistic conditions. This paper describes the main components and...
An Experimental Muon Sourse (EMuS) is proposed to construct at the facility of China Spallation Neutron Source (CSNS) by IHEP (Beijing, China), for the R&D of key technologies of the next-generation neutrino beam facility. The capture superconducting solenoid magnet is one of the key components of the EMuS. It consists of 4 coils which are an axially graded solenoids with a peak central field...
The energy upgrade of the Large Hadron Collider (HE-LHC) and the Future Circular Collider (FCC) demand new requirements that the magnetic field of accelerate magnets should be up to 16 T. The Nb3Sn Rutherford cable is used for magnet design. Due to the complex geometry and working conditions of the magnets, Rutherford cables have to suffer complex stress condition. To better understand the...
A multi-scale mechanical model of Rutherford type, low temperature superconducting cable is discussed in this paper.
The homogenization of the mechanical properties of the superconducting bundle is explained, at room and cryogenic temperature. The inclusion of a high definition three-dimensional sub-modelling of the strand geometry is illustrated, up to the superconducting filaments scale....
In the framework of the High-Luminosity Large Hadron Collider (HL-LHC) project, a complex assembly, known as the beam screen, will be installed by 2024 in the aperture of the new Nb3Sn HL-LHC triplet magnets (MQXF) nearby the ATLAS and CMS experiments. The beam screen is an octagonally shaped pipe that ensures that the vacuum conditions, required for the stability of the beam, are met. It...
The KSTAR central solenoid (CS) is a vertical stack of four pairs of coils compressed axially by preloading structures. The axial compression on the CS coils is monitored by measurements of strain and displacement, which are important monitoring parameters for safe operation of KSTAR. The equivalent vertical force methodology of a simplified multi-spring system was developed to analyze the...
Recently, deposition of REBCO layer on thinner C276 Hastelloy substrate for the second generation high temperature superconductors (2G HTS) wires have attracted more attentions. The main advantages are i) to effectively increase the critical engineering current (Je) without additional efforts on enhancement of current carrying capacity in the superconducting layer, ii) to improve the...
High temperature superconducting (HTS) conductor on round core (CORC) cable is considered as a potential technology for power applications, because of its high current-carrying capacity, compactness, and strong mechanical properties. As the main component of CORC cable, the center core is used to support the HTS conductors. However, for metal center core, the eddy current induced in the core...
The enhancement of engineering current density, Je is one of important issues in conductors for high performance superconducting magnets. In order to obtain the higher Je of high temperature superconducting (HTS) REBCO conductor, we adopted the laminate structure consisting of three REBCO superconducting layers on one common IBAD processed substrate. In this study, we have fabricated various...
Various large current-carrying conductors composed of REBCO tapes have been proposed in recent years for high current applications such as magnets and power transmissions. As one of the conductors, a twisted stacked-tape cable (TSTC) is being developed at the Massachusetts Institute of Technology. The TSTC conductor is composed of stacked REBCO tapes which are twisted along the longitudinal...
We have fabricated Hf and La doped FF-MOD GdBa2Cu3Oy (Gd123) thin films on LaAlO3 substrates and investigated their flux pinning properties. Temperature dependence of Jc in magnetic fields parallel to the c-axis orientation up to 7 T was estimated from the width of the magnetization curves using the modified critical state model. Critical temperature for Gd123 thin films indicated around 92 K,...
We investigated the pinning centers formation in Sm1Ba2Cu3O7-d(SmBCO) coated conductor by reactive co evaporation method. The SmBCO film was deposited on the IBAD-MgO template with the structure of SmBCO/LMO/MgO/Y2O3/Al2O3/Hastelloy using EDDC (Evaporation Using Drum in Dual Chambers) process. We investigated the phase formations as pinning centers with the change of composition ratio of...
In practical applications, the critical current of high temperature superconducting (HTS) tapes is usually influenced by many factors, such as magnetic field, stress and strain, etc. In order to design HTS devices accurately, it is vital to study the critical current behavior of HTS tapes under different conditions. In this work, a series experiments have been performed to study the critical...
This paper introduced a insulation design for a 10kV three-phase concentric high temperature superconducting cables by cold dielectric method. Insulation properties of the PPLP (Polypropylene laminated paper) and its dielectric strengths un-der AC voltage endurance test and the lighting test in liquid ni-trogen have been studied. According to test results and the standard for 10kV paper...
Uniform magnetic field was mainly produced by electromagnetic coils in most engineering applications. However, with the development of superconducting technology, the demand for bulk magnets with uniform magnetic field has increased accordingly. In this paper, the key factors affecting the magnetic field uniformity of bulk magnets have been studied experimentally by magnetizing HTS taped...
Because of the well mechanical property and high current capability, geometrically symmetrical strands made from second generation (2G) wires are promising for large scale high-field magnets typically operated at 4.2 K. This paper performs the first tests of a geometrically symmetrical strand in liquid helium and magnetic field of up to 6 T. The critical current and its anisotropy under...
The CORC wires is one of the most ideal structures and will be used in the next generation controllable nuclear fusion magnets due to the advantages of cheap cooling costs, high transport performance and especially simple manufacturing process. In recent years, the cabling process of CORC has been studied in detail by scholars. However, the superconducting magnet in the fusion reactor is made...
Striation is proved to be effective in the magnetization loss reduction for Conductor on Round Core cable. Though it was experimentally observed that the coupling loss contributed to the total magnetization loss of striated CORC cables, simulation models and detailed analysis of the coupling current were still missing. In this study, we present numerical models of striated CORC cables...
With the performance/price improved, there are increasing market demands and power applications for the cost-effective secondary generation high-temperature superconducting REBaCuO Tapes. In the past decade, main challenges are realized for metallorganic solution-derived (MOD) REBaCuO Coated Conductors to achieve higher critical currents with and without applied fields, such as microcracks or...
Abstract—Due to its excellent performance in critical current, REBCO high-temperature superconductor has important applications in superconducting strands, superconducting cables, superconducting magnets, and superconducting transformers. However,high-temperature tapes are subject to unpredictable mechanical stresses in various applications, and excessive stress will cause permanent damage...
The commercial coated conductors (CCs) are at present available in the form of thin strips with high critical current density and excellent mechanical properties. To realize high current carrying capability, several cable conductors were proposed by assembling a large number of CCs. One of them is so called quasi-isotropic strand consisting of four sub-strands by stacking a number of CCs. In...
Iron free twin aperture superconducting quadrupole in the interaction region is a key technology to increase the luminosity for the high energy particle collider. The Circular Electron Positron Collider (CEPC) that China plan to build in the next 10 years, has the center-of-mass energy of 240 GeV and 33 mrad cross angle at the interaction regions. The beam separation distance at the front end...
The Canted Cosine Theta (CCT) magnet design is typically fabricated by winding individual turns into grooves machined into a metallic mandrel. This allows for precise placement of the conductor for field quality and also provides mechanical support against the Lorentz forces on an individual turn level. A new concept is explored in which the electrical continuity between adjacent turns is...
The Superconducting Linac of the CiADS (China Initiative Accelerator Driven System) project contains parts of quadrupoles with conventional design. The length of the magnets takes up a lot of space on the Linac. In order to make it more compact, a 40T/m Canted-Cosine-Theta (CCT) superconducting quadrupole prototype is presented, which is put into one cryomodule with solenoids. The design...
The High Luminosity LHC (HL-LHC) project, as an upgrade of the large hadron collider (LHC), is to be started in 2020. A set of twin aperture beam orbit corrector with Canted-Cosine-Theta (CCT) dipoles will be developed in China, with a field quality requirement of 10-3 in the two apertures. Cooperating with CERN, a twin aperture corrector is being fabricated as the prototypes before the series...
As a novel superconducting magnet scheme, Canted-Cosine-Theta(CCT) magnet has demonstrated advantages of superior field quality and structure compactness. Combining with Alternating-Gradient (AG) field feature, CCT magnets can be applied to proton therapy gantries with the momentum acceptance significantly increased. This paper will introduce design considerations of a 135 degree AG-CCT magnet...
At CERN the critical current of superconducting wires is measured in four test stations that use high-field superconducting solenoid magnets achieving up to 15 T. The reduction of the measurement uncertainty requires the field mapping of the solenoids in their operating condition. This paper presents the design, manufacture, and application of solenoidal-field transducers based on nested pairs...
The U.S. HL LHC Accelerator Upgrade Project (AUP) (previously LARP) collaboration and CERN have joined efforts to develop high field quadrupoles for the Hi-Lumi LHC upgrade at CERN. The US national laboratories in the AUP program will deliver 10 cryostatted magnets and each cryostat has two 4.2 m long Nb3Sn quadrupoles with 150 mm aperture. The vertical magnet testing facility of the...
Search coils are used for fast and reliable measurements of field integrals as well as integral homogeneities of dipole magnets. A long experience exists at GSI using search coils in series measurements of synchrotron dipoles as well as measurements of dipoles with large deflecting angles.
The biggest advantage of this technique is a direct and fast measurement of the field integral. Current...
A new rotating coil measurement system based on the CMM is developed for measuring the High gradient small aperture quadrupole for the HEPS-TF. The system is located on the CMM's marble platform. The CMM and two Newport translate stages are combined to align the rotating coil to the magnet center within an accuracy of 10 μm. The integrated gradient strength, the field quality and the magnetic...
In the frame of a collaboration agreement between CERN and CEA, the Main Quadrupole (MQ) design of the so-called Future Circular Collider (FCC) has to be investigated. So far, a 2D electromechanical design has been proposed in the FCC Conceptual Design Report [1,2]. Here, the FCC MQ design is further investigated through a 3D electromagnetic design. The integrated field quality over the magnet...
Passive magnetic channel is a kind of beam focusing elements in cyclotron. It consists of several soft iron bars which are magnetized by the main field in cyclotron. One of the common method to design pole shape of the magnetic channels is based on a current sheet analytical model. Geometry parameters of the rectangular pattern pole shape are designed using this model. In this paper, we...
The internal oxidation technique could generate oxide nano particles in Nb3Sn strands, which could significantly refine the Nb3Sn grain size and boost the high-field critical current density. Our recent Ta doped ternary APC Nb3Sn wires with ZrO2 pinning center demonstrated substantial grain refinement and significantly increased Jc,nonCu, while retaining the high Bc2 values of the best...
The generation of nano-scale precipitates from an additional alloying component in the Nb-alloy precursor of Nb3Sn-based wires is considered one of the promising techniques to refine the grain size of the superconducting phase and boost the Jc beyond the specification of a Future Circular Collider (FCC). Much effort by research groups could demonstrate that this technology is viable and can...
The degradations of superconducting properties due to the loading of mechanical stress and strain on the practical Nb3Sn wire are serious problem to apply for the future fusion magnet operated under higher electromagnetic force. Recently, we investigated the internal reinforcement method without reinforcement material using Cu-Sn ternary alloy matrix and found that mechanical strength of...
Nb$_3$Sn superconductor is expected to play a vital role even for next generation high field applications. However, the $J_\mathrm{c}$ is approaching to be fully optimized in terms of cross sectional layout and heat treatment condition. Therefore, some drastic solutions are needed for further improvement in $J_\mathrm{c}$.
We have been studying the effect of the element addition to the...
As a new approach to enhance the Jc property, we have been studying the element addition into the Cu matrix in the internal tin Nb3Sn conductors. We have shown so far that Zn addition promotes the Nb3Sn layer formation, compared to the non-doped Cu matrix Nb3Sn wires.
In this work, we concentrated to investigate the effect of Zn addition on the microstructure during the heat treatment in...
State-of-art magnetic systems of high-energy physics devices require magnetic fields up to 16 T. Attaining the level of fields in the range of 14-16 T is challenging for Nb3Sn superconductors used for such magnets. In order to increase their critical current density in high fields by optimization of the pinning through the modification of the microstructure of the Nb3Sn filaments, doping...
The bronze-processed Cu-Nb/Nb3Sn wires, composed of the Nb-rod-method Cu-Nb reinforcing stabilizer around the Nb3Sn filament bundle, have superior mechanical strength at both low temperature and room temperature after Nb3Sn creation heat-treatment. Therefore, in react-and-wind (R&W) process, the Cu-Nb/Nb3Sn wires are able to be handled easily with applying strains not to exceed the...
High performance Nb3Sn superconducting wires, which have high critical current density and low hysteresis loss, are desired for high-field magnet systems. To meet the requirements, investigations on increasing the Sn concentration in the bronze matrix, improving arrangement of Nb filaments and examining a new design of diffusion barrier were carried out. Wires with critical current at 4.2K and...
Nb3Sn strand have significant applications in constructing high-field (> 10 T) magnets and has great potential value in the next 20 years. Internal-tin (IT) Nb3Sn strand has been developed by many methods for the future fusion reactor after ITER with low hysteresis loss. However, how to improve the current densities of Nb3Sn strand has been becoming an important problem with the increasing...
For developing 14 Tesla whole body superconducting magnetic resonance imaging (MRI) magnet, a new kind of composite conductor has been preliminary deigned. In current design, a structure of Nb3Sn Rutherford cable-in-channel (RIC) conductor is adopted which is similar to Iseult 11.7T MRI conductor. The composite conductor consists of Rutherford cable and cooper stabilizer with channel....
NbTi-based superconducting undulators have been developed and proven to increase the brightness by an order of magnitude at high x-ray energies at the ANL Advanced Photon Source (APS). Nb3Sn has the potential to further enhance the performance of SCUs. These Nb3Sn undulators operate at maximum on-conductor field ranges between 4 T and 6 T; such comparatively low field values present stability...
High-Q operation of Superconducting Radio Frequency cavity reduces power loss at surface and is desirable for CW operation.
For high-Q operation, it is needed to reduce the surface resistance, which is a summation of the BCS resistance and residual resistance. It was found that the residual resistance comes mostly from magnetic flux trapping during cool down process.
A magnetometer called...
Laminated silicon steel sheet, which is widely applied in electrical engineering, such as cores of power transformer and electrical machines, usually suffer from stress caused by a quantity of factors such as non-uniform clamping forces, wavy laminations, or temperature gradients. Therefore, the measurement of magnetic properties under stress is important. A remarkable number of works...
With an operating speed of over 500 km/h and large levitation gap of over 100 mm, electrodynamic suspension (EDS) trains have drawn extensive attention in the railway industry due to these innate merits. The operating performance of the EDS train is strongly affected by the self-excited vibration caused by the varying magnetic field and track irregularity. Being the emphasis of this paper,...
Long wire critical current (I_c) characterization is important for fabrication of superconducting magnets. Many inductive and transport I_c measurement methods have been developed for km scale rare earth cuprate (REBCO) based Coated Conductors (CC), which is the most promising high temperature superconducting (HTS) material for magnet applications. As a direct indication of the current...
A Bitter-like high temperature superconducting (HTS) magnet stacked by RE (RE=rare earth )Ba-Cu-O annular plates and magnetized by flux pump is attractive in application of magnet operating in persistent mode (PCM). Its self- and mutual inductances is essential for calculation of stored energy which has significant something to do with its stability such as quench and recovery as well as...
HTS switch is a critical component for many HTS applications such as flux pumps, fault current limiters. The dynamic response of the HTS switch is a critical to the the performance of the flux pump and fault current limiters. In this study, we build a thermal coupled numerical model for a HTS switch. We use this model to analyse the performance of a HTS switch under different perpendicular...
Two physics experiments using Muon are proceeded in J-PARC, named MuSEUM and g-2/EDM experiments. Objectives of these experiments are to measure hyperfine transitions in the ground state hyperfine structure interval of Muonium and to measure the anomalous magnetic moment of the positive muon, respectively. High homogeneity of magnetic field is essential to achieve the physics goals of both...
The Pulsed Field Facility (PFF)- National High Magnetic Field Laboratory (NHMFL) in Los Alamos, New Mexico has developed and operated a several types of ultra-high field pulsed magnets, including 100 T Multi-shot, 60 T Long Pulse, and an array of small 65 T magnets for users. Separately powering (nested) coils allows to both reduce the driving voltages and have a further degree of control over...
The 64 T with 10ms flat-top magnetic field system driven by capacitor was manufactured and tested at the Wuhan National High Magnetic Field Center (WHMFC). The system consists of the primary circuit and the secondary circuit driven by capacitor banks as they are normally used to generate a pulsed field. The magnet coil and the outer winding of the transformer are connected in series to form...
Traditional pulsed design software, such as PULSE and PMDS, only analyzes the stress distribution on the mid-plane of magnets. The calculations are under the assumption of the constant strain and adjacent materials are perfectly bonded together. These approximate calculations are effective in most cases but cannot take the axial elastoplastic of magnets in consideration and could make...
The Laboratoire National des Champs Magnetiques Intenses (LNCMI) is a French large scale facility, part of the European Magnetic Field Laboratory (EMFL), enabling researchers to perform experiments in the highest possible magnetic field. On its Grenoble site, the LNCMI provides up to 37 teslas combining a PolyHelices and Bitter magnet.
Following the power upgrade from 24 to 30 MW, the...
Inductive pulsed power generators apply coils as powerful short time energy storage which is an ordinary mean to deliver pulses of high power to loads like electromagnetic accelerators1. This article deals with the design, simulation, construction, electrical characterization and a pulsed stress test of a modular toroidal coil. The coil was made from 180 D-shaped copper discs and...
High field pulsed magnets at the NHMFL use high strength conductors up to 90% of its ultimate tensile strength. Therefore it is critical to ensure that the conductor is free of defects for its entire piece length which could be as long as a few hundred meters. It is known that in the wire drawing process, internal crack or so-called ‘chevron crack’ can occur due to unsuitable drawing die...
A previously commissioned system for exploring Ic pressure sensitivity in superconducting cables, the Transverse Pressure Insert, was instrumented and operated to examine signals resulting from strand motion and insulation/impregnation cracking in a fully-excited single strand embedded in an insulated and impregnated Rutherford cable stack at 4.2 K with transverse pressures up to 250 MPa and...
Motivated by our previous works, 26.4-T 35-mm and 18-T 74-mm ultra-high field no-insulation (NI) stand-alone magnets wound with 2G REBCO, we recently embarked on a new project to develop a 35-T NI REBCO standalone magnet. We published a design of a 35-T 40-mm winding bore magnet in 2017. Owing to the large average current density of the magnet (365 A/mm2), the magnet became highly compact; the...
The objective of this work is to discuss the engineering feasibility of high-frequency magnets for the magnetic hyperthermia cancer therapy. For effective induction heating properties of cancer therapy, the target specifications of the high-frequency magnet system are 0.06 T of the peak magnetic flux density with 200 kHz of the operating frequency at the center of used space. The operating...
High-temperature superconducting magnet technology are developing fast, especially using REBCO tapes. This paper present a new design of a HTS coil. The coil is made of stacked REBCO plates and operates with power supply, which works like a conventional resistive coil. The structure design and construction details was then described herein. The advantage of this design is its low inductance...
With manufacturing process development of the high temperature superconducting (HTS) tape, the hundreds meters HTS tapes are applied in industry, especially beneficiation. It cannot effectively improve the work efficiency of the material purification and separation, but also solve the problem that some weak magnetic materials are difficult to separate due to the so high magnetic intensity and...
Abstract: A laboratory solenoid magnet was designed and tested in this paper to explore the feasibility of ReBCO tapes applied to detector magnet technology. The magnet consists of several double pancake coils, which adopted to No-insulation winding method. The outer and inner radius were 240 mm and 150 mm, respectively. We conducted a series of experiments on the prototype to investigate the...
The Central Solenoid (CS) model coil, which is responsible for developing and verifying the larger-scale superconducting magnet technology of China Fusion Engineering Test Reactor (CFETR), has been designed and is currently being manufactured at ASIPP. In case of an emergency shut-down like in succession of a quench, the voltage across the coil may rise to about 2.5kV. Therefore, the coil have...
In the HTS superconducting magnet application fields like motors, generators and SMES, 2G coated conductor (CC) tapes will be subjected to alternating stress or strain during manufacturing and operation. The repeated load affects the mechanical integrity and eventually the electrical transport property of CC tapes. In the design of coils and magnets under magnetic fields, both the yield...
High-temperature superconducting magnet coils made with Sumitomo Type HT-NX are complex composite structures composed of Bi-2223 conductor filaments, silver matrix, solder, nickel-alloy laminations, polymer insulation, and epoxy or wax. The mechanical properties of these composites are required inputs to a correct stress analysis. Mechanical test specimens composed of several layers of...
Previously we reported the “Defect-irrelevant” behavior of a no-insulation (NI) high temperature superconductor (HTS) pancake coil in 2016. The test coil was wound with REBCO tapes having multiple “defects” and tested in a bath of liquid nitrogen at 77 K. Coil terminal voltages and magnetic constant of the test coil are essentially identical to those of its “healthy (defect-free)” counterpart...
MgB$_{2}$ bulk magnets have been strengthen by the densification, grain refining, and chemical doping. Ti-doped MgB$_{2}$ bulk fabricated by an in-situ hot isostatic pressing (HIP) method also offered the high trapped field, B$_{\rm T}$ of 3.6 T at 13 K [1]. The carbon doping is also well known to bring about the pronounced increase of both the critical current density J$_{\rm c}$ and the...
Hyper Tech Research will report on progress that has been made on developing magnesium diboride superconductor wires, coils and magnets for commercialization efforts, with a specific emphasis on conduction cooled MRI and AC motor/generator applications.
In the drawing process, a non-uniform powder distribution in the MgB2 wire along longitudinal direction can cause degradation of superconducting properties of MgB2 wire and strain hardening of sheath material. It may finally results in breakage of wire due to a stress concentration at locally deformed region in sheath materials. In this study, numerical simulation of drawing process of...
The performance of MgB2 wire (O.D. = 0.67 mm, Length = 8 km) made for a prototype solenoid magnet for X-band (12 GHz) klystron are presented. This solenoid magnet is fabricated by using Wind & React method and is operated as a cryogen-free magnet at 20 K. In this paper, tensile- and bending-stress tolerances of the non-reacted wire and the properties (Ic-B-T, RRR and homogeneity) of the...
In this paper, the km-grade 30-core MgB2 superconducting wire with a diameter of 1.0mm has been prepared by conventional in-situ powder-in-tube method. The metallographic analysis results show that the 30-core MgB2 wire has very good uniformity in both transverse and longitudinal directions, and the critical current (Ic) and critical current density (Jc) reach 95 A and 2.1×105 A/cm2 at 4.2 K...
MgB2 strands have been highly developed commercially, providing great interest in superconducting magnetic energy storage (SMES) applications with low cost by using liquid hydrogen (LH2) as a coolant due to the higher critical temperature compared to the boiling temperature of the LH2. Therefore, the MgB2 SMES is promising device, giving us a remarkable synergy effect by combining the...
In order to reduce the long-term annealing process and prevent excessive grain growth, we attempted to fabricate MgB2 superconducting wires by the rapid heating and quenching (RHQ) method.We have successfully synthesized kilometer-length 6+1 filamentary MgB2 wires reinforced and toughened by Nb/Cu composite with in-situ powder-in-tube method, and for the first time applied the rapidly heating...
Multifilamentary Magnesium diboride (MgB2) wires are composed of brittle compound filaments and metallic sheath with a sufficiently strong reinforced material. A strong reinforced material provides tolerable stress that increases the filament density and enhances the grain connectivity of the MgB2. However, MgB2 wires are highly attractive for various applications due to its high critical...
The Tc of MgB2 superconductors, 39 K, is higher than low temperature superconductors such as NbTi and Nb3Sn, which can allow operating at 20 K by using refrigeration system without the consumption of expensive L-He. In addition to the high Tc, MgB2 has the advantages of longer coherence lengths and the lower anisotropy effect, when compared with the high temperature superconductors, and the...
For the high performance of the wires, cables, and further to the various magnet applications of MgB2 superconducting materials, the important issues have been addressed on the raw precursors of their purity, relative sizes, crystallinity, and the surface conditions including MgO and B2O3 impurities. Since in situ MgB2 superconducting wires have been fabricated using the reaction of Mg and B...
Iron-based superconductors (IBS) are attractive for high-field applications due to the good performances including high upper critical field and low anisotropy. This work describes electro-mechanical properties of the silver-sheathed multifilamentary Ba0.6K0.4Fe2As2 (Ba-122) tape. This tape was fabricated by the ex-situ powder-in-tube (PIT) method and the number of filaments is 7. In order to...
Composite MgB2 wires have been now commercialized by a few industries in the world. In order to use them for applications, it is necessary to evaluate their mechanical property together with critical current and its stress / strain dependence. In the present study, the mechanical properties of three kinds of commercialized MgB2 wires were mainly evaluated. Their observed Young’s moduli...
Ac losses and shielding currents affecting field qualities in coated conductors are concerns in accelerator magnets which must be excited repeatedly. We carried out repeated excitation experiments of a test magnet for accelerator applications of coated conductors. The magnet consists of a pair of 4-stacked racetrack coils with iron return yoke at low temperature region. It can generate 2.4 T...
High temperature superconductor (HTS) No-insulation (NI) shows a great advantage on enhanced thermal stability. It is promising to improve the stability and safety of HTS machines in electrical aircrafts. A Marie Curie project under Horizon 2020 was started to develop highly safe HTS machines based on NI technique for electrical aircraft. A 2MW HTS synchronous motor prototype was developed...
It was found that arranging filaments in a multifilament Nb3Sn conductor under a specific angle or twist pitch length, the strain sensitivity of the critical current can be removed. The physical reason is that at such an angle the distortion of the Nb3Sn crystallographic unit cell, which is responsible for the reduction of the critical current under strain, is zero and independent of the...
The traditional approach for developing high field magnet technology has been to build a new magnet with some variations in design parameters or in material. Building a high field magnet is time consuming and expensive. This limits the development and demonstration of a new design or technology and/or forces several changes to be made at the same time which limits the clear interpretation of...
After over 50 years of application, Nb₃Sn remains by far the most economical superconductor for magnetic fields beyond the reach of Nb-Ti but new challenges such as the Future Circular Collider, FCC, require critical current density (Jc) values well-beyond what is possible with available commercial Nb₃Sn wire. Furthermore, future high field magnets will also require higher Jc margins to allow...
Electric propulsion systems are attracting much attention as a revolution in the aviation industry. The key components of this revolution are electric motors and generators. However, conventional machines are limited in their rated power, power density, and are not suitable for aircraft because of their size and weight. High-temperature superconducting (HTS) power machines have the advantages...
Accelerator magnets made of state-of-the-art Nb3Sn strands unveil relatively long training. This could be due to the low stability of high-Jc Nb3Sn wires to flux jumping provoked by mechanical perturbations in the magnet coils and/or by epoxy cracking. Conductor stability to flux jumps can be increased by reducing the superconductor filaments size while maintaining low resistivity of the...
Future hybrid and all electric aircraft require superconducting electric motors and generators in order to most readily attain power densities above 10 kW/kg, preferably at operating temperatures of >40K. Although the rotor operates at fields of up to 5 T, because it is DC, it can be wound with HTS tapes, for example 2G, that can generate these fields at > 40 K. The stator, however, operates...
In order to address the needs of next generation particle accelerators, high $J_E$ ($>1000$ $A/mm$$^2$ at $5$ $T$ [1], [2]) HTS Bi-2212, with application of novel quench detection and protection methods is utilized in sub-scale accelerator magnets. A series of racetrack coils (RC 1-6) with the same geometry have demonstrated conductor improvements resulting in a factor of four increase in...
The development of Nb3Sn wires doped with artificial pinning centres (APC) from binary to ternary compounds is reported. ZrO2-doped tube-type (TT) and powder-in-tube (PIT) were manufactured by Hyper Tech Research Inc. with the aim of reaching the FCC requirements (non-Cu Jc=1500 A mm-2 at 16T and 4.2K). Short pieces of the wires were characterized by means of SQUID magnetometry in order to...
Trapped magnetic flux magnets made by stacking high temperature superconducting tape portray an easy assembly with already available materials, high mechanical resistance, provided by the substrate and improved thermal stability, which enhances the trapped flux compared to bulks and allowed reaching the world record of 17.7 T [1]. The presented analysis will expand the work of Patel et al. [2]...
In collaboration with Advanced Conductor Technologies, the U.S. National Magnet Development Program is developing REBCO magnets with a goal of generating 5 T dipole fields. We have built several subscale magnets based on the Canted-Cos-Theta (CCT) concept using commercial REBCO Conductor on Round Core (CORC®) wires. The latest magnet C2 has four layers and a designed dipole field of 3 T in an...
Rutherford cables based on high critical current density Jc Nb3Sn wires are considered for next generation accelerator dipole and quadrupole magnets. The operating magnetic field of these magnets is expected to be significantly larger than that of the Nb3Sn magnets developed for the High Luminosity – Large Hadron Collider (HL-LHC) project, which is about 12 T. In particular the present...
The consortium of the Advanced Superconducting Motor Experimental Demonstrator (ASuMED) will develop, build and test the first fully superconductive motor for aerospace applications. The cryogenic topology of the motor is based on a dual-cryostat concept, which consists of two separate cryostats for the rotor and stator. The rotor cryostat design is particularly challenging because of the...
In 2018, FRESCA2 dipole magnet, developed within a collaboration between CEA Saclay and CERN to provide a background field for tests of cables and small coils, reached a field of 14.6 T. This represents a new world record field for dipole magnets with a clear aperture. As a continuity of the European project EUCARD-2, CERN aims at exploring accelerator magnet technology up to a 20 T operating...
Iron-based superconductors (IBS), especially 122 type, are very promising candidates for high-field applications because of its ultrahigh Hc2 > 70 T at 20 K, low anisotropy ( < 2 for 122) , and ease of fabrication. Recently, thanks to the great supports from Chinese government, significant progresses on the IBS wires have been made, in terms of both Jc enhancement and practical research. In...
Low speed direct drive generator has been widely used in the renewable energy power generation, due to the advantage of no gearbox. Our group has studied so-called high-temperature superconducting induction/synchronous motor (HTS-ISM), which has the advantages of high efficiency, high torque density and robustness against overload. Especially, its highly efficient generation characteristics at...
Shielding-current-induced fields (SCIFs) in magnets wound with coated conductors are one of the most serious problems for application. SCIFs cause changing of magnitude of magnetic field, error field components, and drift of magnetic field during when transport current is constant. Especially, because magnets for accelerator systems are sometimes required to generate precise magnetic field...
Iron-based superconductor (IBS) is expected to be the next generation high temperature superconductor with their potential good properties for the high-field application. This study focus on exploration of the characteristics of IBS coils at high field and development of the IBS coil fabrication technology. A series of ϕ35 mm IBS coils including single pancake (SPC) and double pancakes (DPC)...
A levitating superconducting bearing assembly is being designed, built and tested to support the rotor of a 10 kW laboratory-scale prototype of a 25,000 rpm superconducting hybrid electric aircraft motor targeting an ultimate power rating of 1 MW. To this end, we have constructed a bearing test rig enabling measurements of the levitation force and stiffness of assemblies of state-of-the-art...
In 1973 A.D. Appleton writing in the Journal Philosophical Transactions of the Royal Society in London heralded the dawn of a new age of electrical machines with the title “Superconducting Machines – a new era for the electrical power industry. This was written in the very early days of the development of Niobium Titanium and records that the world’s very first superconducting machine was a 37...
In this paper, a novel Uniform Pressure Actuator (UPA) is designed and analyzed based upon the manufacturing technique of pulsed magnets, which has high forming efficiency as well as high strength. The UPA is a specially designed coil for use in electromagnetic forming (EMF) process, which offers a uniform pressure distribution in flat sheet forming. To improve the strength of the coil,...
Pulse current driven forming (PCDF) is a forming method that directly loads a pulse current into two parallel placed workpieces, and the mutually exclusive electromagnetic force between them causes the workpieces to be deformed. Compared with electromagnetic forming (EMF), this method can improve the current density in a low-conductivity workpiece. However, the magnetic field is low due to the...
The Direct-Current Current Transformers (DCCTs), which is based on the magnetic flux compensation, are the most sophisticated instruments to measure currents. In order to achieve the precision measurement of the magnet current in the flat-top pulsed high magnetic field (FTPMF) facility, the DCCT based on magnetic modulator with the range of 30kA is developed. In the conventional high...
High magnetic fields is a basic and indispensable research tool, which has been used in physics, medicine, biology, and other corresponding sciences as an extreme condition. Wuhan National High Magnetic Field Center has been working on the research of high pulsed magnetic field and designed the 100 Tesla system to achieve higher magnetic field. The magnet adopts a three-coil structure, which...
Wuhan National High Magnetic Field Center (WHMFC) has been working on high pulsed magnetic fields and designed the 100 Tesla magnetic system. The magnet adopts a three-coil structure and the outer coil is powered by a pulse generator rectifier. In order to ensure the temperature rise of the coil is reduced, the energy stored in the coil needs to be quickly released after the combined magnetic...
Cu-Ag and Cu-Nb composites, which have been successfully used in high field magnets, reach their most desirable strength level when their interface spacing is below 100 nanometers. The usual fabrication methods for these composites are either cold rolling or cold drawing, both of which refine interface spacing and create anisotropy. These methods may also introduce shear-bands into the...
The Central Solenoid Model Coil (CSMC) of the China Fusion Engineering Test Reactor (CFETR) is currently in the manufacturing process. After the manufacturing completed, the CSMC will be test on the testing platform. This platform consists of several subsystems, in order to keep the system safe and to avoid any failure possible to damage CSMC magnet during the experiment, we have designed the...
Superconducting magnets at CERN are being tested in one of the largest testing facilities around the world known as SM18. The test facility is equipped with ten horizontal test benches, five vertical cryostats and a cryogenic feed box allowing to test the superconducting link in He gas. This unique infrastructure requires a well-designed and optimized quality assurance and control system to...
The HEPdipo magnet is being designed within a collaboration among CERN, EPFL-SPC, F4E and LBNL. The goal is to provide, with a background field of 15 T, the capability of testing insert coils and cables for high energy physics and fusion applications at variable temperature.
The target field of 15 T is generated at 4.2 K over a bore aperture of 144 mm × 94 mm and a length of about 1 m. The...
“China Fusion Engineering Test Reactor (CFETR)” is a new generation of tokamak which aims to bridge the gaps between the fusion experimental reactor ITER and the demonstration reactor (DEMO). The superconducting magnet system is the core component in tokamak and future fusion reactor, and the superconducting magnet system for CFETR will be a big challenge due to the higher magnetic field is...
A versatile facility capable of providing cryogenic-electro-magnetic multifields had been successfully constructed for investigating the field-dependent and mechanical properties of superconducting wires and tapes at Lanzhou University, China. It can generate a 3.5T transverse background field, and continuous variations of temperature (4 to 77K, ~5K/min) and transport current (0 to 700 A,...
The operation of next generation accelerator facilities like the Facility for Antiproton and Ion Research (FAIR) around the world requires novel approaches for instrumentation to survive the expected radiation doses in, for example, secondary beam production regions. As particle beams at high energies are guided with strong magnetic fields one key piece of instrumentation is a precise,...
A rotating coil measurement system was developed for the DC magnets of the CSNS accelerator. This system solves the compatibility problems of different center heights, masses, effective lengths, and magnetic field strengths among CSNS bulk magnets. After testing, the repeatability error of the integral field measurement is less than ±0.02%, the repeatability error of harmonics are less than...
Many superconducting devices operate in persistent mode. Heat losses from current leads are one of the major design challenges, especially when limited low-volume cryogen is available during normal operations. To reduce the heat losses, the current leads are either retracted after charging, or have permanent leads carrying smaller current when in a charging mode but have small heat load when...
The automation of magnetic measurements prevents human operator errors from impacting measurements and ensures the repeatability of the measurements and the traceability of the results to specific measurement scenarios. The presented approach achieves automation via parametrized scripting; this offers the user additional flexibility by providing the ability to define families of measurements...
This paper presents a numerical method to calculate spatial harmonic coefficients of magnetic fields generated by screening currents in a high temperature superconductor (HTS) magnet. First, current density with screening currents considered in the individual turns of an HTS magnet is calculated using the 2D axisymmetric edge-element formulation and the domain homogenization technique. With...
Accurate and reliable magnetic field measurement is of great significance at various stages in the lifetime of accelerator magnets. The method of search coils is the most widely used on the magnetic measurements. Traditional search coils are machined and/or hand-wound, which have the poor repetition and weakness in the precision of the coil geometry and position. To overcome these issues, the...
In an HVDC high-temperature superconducting (HTS) cable composed of polypropylene laminated paper (PPLP), a butt-gap which is unavoidable in the fabrication process may lead to form voids. When dc voltage higher than partial discharge inception voltage (PDIV) is applied, partial discharge occurs in the void. If void discharge sustains, the electrical ageing of PPLP accelerates, and eventually...
Abstract: Temperature measurement is very important for the state monitoring and safe operation of High Temperature Superconducting (HTS) cables. Distributed optical fiber can be used to measure the temperature along power cable because of the advantages of anti-electromagnetic interference, high voltage resistance and convenient fixing, etc. In this paper, the feasibility of distributed...
The no-insulation (NI) winding technique improves the thermal stability of REBCO pancake coils. A radial bypass current protects an NI pancake coil from burning-out when it turns a normal state. That is, the characteristic resistance (turn-to-turn contact resistance) of NI REBCO pancake coil characterizes the electrical behavior inside the coil as a function of “self-protecting.” To estimate...
Compared with other magnetic materials, nanocrystalline alloy has specific advantages. It can be made into strips that much thinner than silicon steel sheets and its conductivity is lower, which effectively reduces the high frequency loss. The permeability of nanocrystalline alloy is higher than that of ferrite, so the capacity and power density of the equipment made from nanocrystalline...
A hypothetical ground fault in the superconducting (sc) magnet system of Wendelstein 7-X would shift the midpoint of the grounding system and therefore increase the voltage to ground during a fast discharge of the sc magnet system. As this voltage could endanger the high voltage integrity of the sc magnet system, an In-Service-Test system has been developed to monitor the insulation of the sc...
In order to develop and verify the key techniques and manufacturing process of the full-size central solenoid (CS) coil for China fusion engineering test reactor (CFETR), the central solenoid model coil (CSMC) project has been launched in the Institute of Plasma and Physics, Chinese Academy of Sciences (ASIPP). The CFETR CS model coil is a hybrid superconducting magnet of 12 T maximum magnetic...
High-temperature superconductors (HTS) are promising candidates for use in the high-field magnets needed in thermal nuclear fusion reactors. Their high critical temperatures allow them to operate at temperatures far above 4 K and ease requirements on nuclear heat generation and heating during ramping of the magnetic field. Other benefits compared to low-temperature superconductors include...
Joint resistances of eight short samples have been measured until 2018 as a qualification test for ITER Toroidal Field (TF) coils. The joint sample consists of two short TF conductors with the length of 1.535 m, and each conductor has two joint boxes at both ends. The lower joint is a testing part that is full size joint of the TF coil. The upper joint is connected to 100 kA current leads of a...
The ITER Central Solenoid (CS) will be one of the world’s largest and most powerful pulsed superconducting electromagnet ever built; at an approximate weight of 1300 tons and a total height of 18 m consisting of a stack of six electrically independent 4.1 m diameter modules. In order to electrically connect the CS with the feeder busbars, 12 twin box joints are used to assure an efficient high...
The ITER Central Solenoid Modules (CSM) are being fabricated at General Atomics (GA) at their Poway, CA Magnet Technologies Center. Each of the seven modules will undergo final testing at the GA facility to demonstrate their performance with full current of 48.5 kA, 11 T and at 4.5 K. In order to perform tests on multiple modules, a demountable coaxial joint using indium wires was developed to...
Abstract: In the superconducting magnets system of the International Thermonuclear Experimental Reactor (ITER) project, the heater chains are used to avoid heavy condensation or ice formation on the current leads of feeder. As an insulating and heat-conducting component, the heater chains should satisfy electrical insulation and thermal conduction properties at the same time. Due to no...
The ITER Central Solenoid (CS) has terminal butt-type joints called Coaxial joints. It was decided to study a design of this joint with rutherford shunts, and to build models for its resistive and inductive behaviors. In particular, the behavior of the joint under magnetic field transients is investigated with various analytical models that are compared with a FEM model. The key point of the...
Nowadays, although the fabrication techniques of high temperature superconductors have been far developed, Bi2Sr2Ca2Cu3O10 (Bi-2223) high temperature superconducting tapes are still the ones the most mature fabrication technique and the most stable batch production ability, not to mention their stable mechanical configuration. Therefore, for the construction of many big scientific facilities,...
At present, Ag- sheathed Bi2212 is considered as the most suitable superconducting material to alternate the Nb-based material for the CICC conductor operation with the magnetic field higher than 20T. However, the Bi2212 round wire application technology development encountered difficulties, due to the complicated Bi2212 CICC manufacturing processes, the low mechanical performance as well as...
Abstract-High temperature superconducting material Bi 2212 has outstanding conductor-carrying capacity at 4.2 K in magnetic field and it is the only high temperature superconducting material that can be made into isotropic round wire (RW). Therefore, it’s considered to be one potential material for CICC (Cable-in-Conduit Conductor) in high magnetic field application, especially when magnetic...
China Fusion Engineering Test Reactor project (CFETR) , the next generation of Tokamak of China, has been incorporated into the important development of nuclear fusion in the future. Compared to low temperature superconducting materials, Bi-2212 is more promising due to the high irreversible field and outstanding current-carrying capacity. In particular, its critical properties can be improved...
Bi2Sr2CaCu2Ox (Bi2212) has the excellent current carrying properties at 4.2K and is one of the potential materials for superconducting magnets. In the construction and use of magnets, superconducting wires are subjected to complex stresses, so it is important to determine the mechanical properties of the wires. In this paper, the mechanical properties of Bi-2212 wire before heat treatment and...
A quantitative knowledge of the intra-wire transverse resistance is essential for a proper characterization of multi-filamentary Bi2212 round wires, and a better understanding of their performance in short sample tests and thus inter-strand current redistribution in cabled conductors.
Intra-wire resistance and AC loss of various multi-filamentary Bi2212 round wires have been measured and...
Bi2Sr2CaCu2Ox has excellent electromagnetic properties under high magnetic field, and can be made into isotropic round wire (RW) form. Therefore, it is easy to use cabling technology to make them as cable in conduit conductor (CICC) for the next fusion reactors. However, the Bi-2212 phase is a ceramic structure and sensitive to strain. In application, Bi-2212 RW will be affected by thermal...
High-temperature superconducting material of Bi-2212 (Bi2Sr2CaCu2Ox) is considered to be used in the next generation of fusion reactors such as China Fusion Engineering Test Reactor (CFETR) due to extremely high critical current density as well as high critical field at low temperature. The critical current as well as its inhomogeneity is one of the important factors to evaluate the...
Linear generators are extensively applied to direct-drive wave energy converters (DD-WECs). Low power voltage and power density can be considered the main drawbacks of DD-WECs given their low direct-drive speed. To increase the output voltage and power, and reduce the number of PMs, a double-sides stator PM linear generator is proposed and researched in this paper, based on stator flux...
Superconducting generator (SCG) technology is being proposed for large direct-drive offshore wind turbines due to their compactness and light weight. However, SCGs have intrinsically large magnetic air gaps and therefore produce unacceptably high torque during a short circuit. Among possible solutions, using fractional-slot concentrated windings (FSCWs) can reduce the short circuit torque to...
A 10 MW class HTS wind power generator is under development in Korea using REBCO wires for off-shore installation. NI (No-insulation) winding technique is applied to increase the electrical and mechanical stability of the rotor magnets using REBCO wires. The REBCO magnets, having operating temperature around 35 K, are designed to be cooled using forced circulation of cold helium gas. The cold...
Offshore wind power, as a clean and renewable energy, has become the main growth point of wind power development. It is a trend, for offshore wind power, that large power even above 10 MW wind generators are preferred to reduce the cost per MW. Due to the advantage of much higher magnetic loading in the high temperature superconducting (HTS) machine compared to that of the regular machines,...
High temperature superconductors (HTS) are being applied to electric power systems such as generators, motors and reactors. Researches on HTS wind turbine generators are now focused on increasing efficiency and capacity. In the HTS generators, a large magnetic air gap exists because of needed space for a cryostat wall and thermal insulation. Consequently, the reactance is lower than that in a...
Software-based simulations, such as finite element method (FEM), can identify the electromagnetic forces generated by high-temperature superconducting (HTS) coils in a generator, but structural errors can occur in actual manufacturing processes based on the simulation results. Because large wind turbines have high torque, the structural errors in the manufacturing process can cause fatal...
In order to improve the power density and efficiency of the existing generator for wind power generation, a novel double stator brushless doubly-fed generator with back-to-back cage-barrier rotor has been presented not long ago. However, the accident of toughing between inner stator and rotor inner cage-barrier has been found in the process of experiment for prototype, which results in large...
In order to saving energy and reducing consumption, making full development of advanced materials has been a global consensus. Nanocrystalline alloys, compared with ferrite, have high permeability, high saturation flux density and relatively low core loss. Due to the lack of magnetic properties under complex working conditions, its application in high power density applications have been...
Prototype tests are underway to study the feasibility of using a bulk magnetic system to maintain a transversely polarized target within the longitudinal solenoid of the CLAS12 detector, during an experiment to measure transverse spin effects in semi-inclusive deep inelastic scattering (SIDIS) at 11 GeV. The experiment has been approved with the highest priority rating at Jefferson Lab. The...
The High-Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP) is preparing for production of the US-contributed Q1 and Q3 Interaction Region Quadrupoles (MQXFA). These magnets are based on Nb$_3$Sn conductor and need to satisfy stringent requirements for operation in HL-LHC. Magnetic field measurements are performed during magnet assembly to monitor key parameters such as integrated...
Conductor on Round Core (CORC(R)) wires are attractive for applications to accelerator magnets because of their large current capacity and mechanical flexibility. Because accelerator magnets are sometimes required to generate time-dependent magnetic field, ac losses and their distributions in the magnets can be problems. Because coated conductors composing CORC(R) wires have three-dimensional...
High-temperature superconducting (HTS) composites are being considered for use in high-field magnets for future particle accelerators, as they allow the development of very high field dipoles and quadrupoles. As part of the US Magnet Development Program, LBNL is developing Bi2212- and REBCO-based insert magnets towards 20 T hybrid dipole magnets. The field quality of the magnets is important...
High-temperature Superconducting tapes with high critical currents have shown a potential to be used as high-field magnets. HTS ring magnets have been proposed to use as a trapped field magnet with persistent current flowing in them after magnetization. The advantage over conventional HTS bulks is that the HTS ring magnet can be flexible in size and easy to build. This work focuses on...
Superconducting winding are enabling for the development of the highest power density motors and generators for aircraft use. It is presently estimated that motors with normal conducting can reach a future limit of at best 20 kW/kg. On the other hand, superconducting winding are estimated to be able to produce more than double this, at 45 kW/kg. Superconducting windings carry very large...
Striation is one of the approaches to reduce ac losses and shielding-current-induced fields (SCIFs) in conductors or coils made with coated conductors. If filaments in a striated coated conductor are decoupled, the magnetization of the coated conductor is reduced, and, then, the ac loss as well as the SCIF is reduced. Striated coated conductors can be classified into two types: one in which...
High Temperature Superconducting (HTS) generator for a large-scale wind power generation system draws much attention as a contemporary research item. Metal-Insulation (MI) technique greatly enhanced the thermal stability of the coil without requiring complicated protection against quenching because quench currents are bypassed through the turn-to-turn contacts, ultimately improving the...
The superconducting synchronous generator is one of the breakthrough elements for direct-drive wind turbine because it is light and small. Normally the superconducting one has copper armature windings in the stator and superconducting field windings on the rotor. The electrical frequency of the output voltage of the direct-drive generator is very low, so the total length of the armature...
Offshore wind energy is going to take the dominated place in renewable energy due to it abundant and steady wind resource. To reduce the levelized cost of energy, the large power rate, even above 10 MW, wind generators are preferred for offshore wind farms. Compared with conventional wind generator such as induction generators and permanent magnet generators, high temperature superconducting...
Nowadays, wind energy is developing rapidly as it is clean and renewable and the offshore wind energy is one of the most popular ones for its abundant source. To avoid frequent maintenance of the offshore wind turbine system, a large direct-drive generator is needed. Due to the advantages of the higher magnetic field in the high temperature superconducting (HTS) machine compared to that of the...
Fully-superconducting generators with compactness and lightweight are promising candidates for direct-drive multi-mega-watt offshore wind turbines due to its high current density properties. The compactness and lightweight design should bring about the cost reduction of nacelles, towers and foundations. Furthermore, high-performance REBa2Cu3Oy (REBCO: RE = rare earth) tapes and the reduction...
A high torque density enables high temperature superconducting (HTS) generators to be a strong candidate for lightweight, efficient and cost-effective large direct-drive (DD) wind turbines, especially for the next-generation floating wind turbines where a less top head mass is appreciated.
It is very common that 3-phase armature windings are used in HTS generators. One consequence is that AC...
The joint between two RE123-coated conductors with crystalline joint by melted bulk (CJMB) method [1, 2] has been developed for NMR and MRI. In this method, a Yb123 sheet is used between the coated conductors as a superconducting intermedium. We reported that a superconducting joint with critical current of 21.2 A at 77 K was obtained, and the persistent coil has a low resistance about 1 pΩ in...
Superconducting joints are extremely important for the application of HTS magnets. Recently, various joint techniques have been proposed for connection between HTS conductors. However, suitable evaluation methods for joint resistance (R$_j$) have not been established. We have developed a joint resistance evaluation system [1]. The system consists of an HTS sample with a joint, a current...
Various types of coated conductor (CC) joints are required due to current CC tapes fabrication limited lengths and for their coil applications in high field magnets. It is essential that some CC joint fundamentals, including joint resistance, must be a consideration in dealing with such application designs. Also, joint requirements must meet both the conditions of good electrical and...
The low melt temperature REBa2Cu3O7-δ (LMT RE123, RE=Yb, Er, etc.), a candidate of the joint materials, is essential to acquire superconducting joint of the 2nd HTS tape, which could be used in extreme high field NMR (≥25T). In this paper, two LMT RE123 materials have been synthesized. The synthesis parameters have been optimized to obtain RE123 materials with high superconducting properties....
A novel Nb3Sn superconducting jointing method by means of powder metallurgy was presented to reduce the resistance for purpose of satisfactory magnetic field stability of high field NMR instrument. In this research, Nb, Sn and Cu element powders were introduced in ball milling processing to prepare the (Cu, Sn) solid-solution before pressing and sintering. The A – 15 type Nb3Sn phase was...
A superconducting joint technique has been extensively investigated to operate magnetic resonance imaging systems in persistent current mode, which enables a high-resolution level of the magnetic field. We have presented the MgB2 superconducting joint with unreacted MgB2 wires that demonstrate the feasibility of the joint technique to be utilized for the MgB2 MRI magnet development. However,...
SST-1 is a medium size superconducting (SC) tokomak operational at IPR in India. TF and PF sc coils are used to produce high magnetic field strength. Presently, 10 kA rated Vapour cooled current leads (VCCLs) for TF system is made of NbTi superconductor and copper heat exchanger. Similarly, 9 PF coils will be energised by individual power supplies requiring total 18 VCCLs under pulse...
Current lead’s Joule-heating and conduction losses are main parts of superconducting cable’s cryogenic system total heat load. Superconducting energy pipeline is a new type of hybrid superconducting energy transmission cable, and the heat leakage of its current lead is not negligible.
In this paper, the process of superconducting energy pipeline current leads design, optimization and...
For the Beijing Spectrometer III (BESIII) superconducting magnet alternate upgrade project, two 4kA HTS current leads were designed, manufactured and tested. The baseline design of the current leads adopted a stacked YBCO conductor solution to achieve a lower thermal load at 4K, improve the stability of the magnet, and meet the requirements in the upgrade project that the unchanging of...
The design, analysis and experimental test of a High Temperature Superconductor (HTS) current leads with parallel HTS tapes is presented. Two HTS tapes are electrically shunted in parallel in each positive and negative lead respectively to increase its current-carrying capability. It is essential to enable balanced current sharing between the parallel HTS tapes to prevent potential overload...
Recently, the magnitude of the fault current in the grid has been increased due to the development of the electric power industry and the increase of the distributed power generations. Since the increase of the fault current may cause a bigger accident than the capacity of the existing installed protective equipment, it is necessary to replace the protective device with a larger capacity or...
Recently, flexible DC transmission has been developed rapidly in the Off-site grid interconnection. Inhibiting the sudden increase of DC current caused by short-circuit faults is necessary for the protection of power grid. Generally, the short-circuit faults may be caused by physical conduction or arcing and sparking. To address permanently damage the power grid, a resistance type...
To secure the reliable dissemination of the dc microgrid system, it is essential to establish efficient protection scheme. There are various protection methods of dc microgrid system : fuse, circuit breaker (Solid-state, Mechanical, Hybrid, etc.), superconducting fault current limiter (SFCL) and fault tolerant converter. Among the mentioned methods, the mechanical circuit breaker (MCB) has the...
In this paper, the flux-lock type superconducting fault current limiter (SFCL) with the mechanical switch (MS), which can be driven by self-driving coil to drive the MS unlike the previous SFCL, was suggested. The operational principle of the suggested SFCL with the MS is same as one without the mechanical switch, except that the MS is driven by electromagnetic repulsion force generated by the...
We have studied a DC circuit breaker with an HTS fault current limiting (FCL) module for 30 kV MDVC power grid. The attached FCL module can reduce the burden of the circuit breaker to make the system break the fault current faster as well as safer. In this paper, we will present the design of an HTS fault current limiting module with 2G REBCO conductor for the MVDC power grid with the rated...
This paper proposes a superconducting coupled DC circuit breaker that combines a superconductor with a mechanical DC circuit breaker for DC fault current interruption. The power burden and damage possibility of superconductors are determined by the recovery characteristics of the superconductor during the reclosing operation of the proposed circuit breaker. They also affect the breaking...
We propose arc-induction type DC circuit breaker combining the magnets as the mechanical circuit breaker suitable for the DC system. This circuit breaker simply composes the mechanical contacts, the induction needle, the ground wire and magnets. The arc is moved the induction needle according to the Lorentz’s force and it is inducted to the induction needle. The induced arc is flowing into the...
Since DC has no current zero point, an arc occurs when the DC circuit breaker performs a cuf-off operation. In this case, a fatal fault may occur in the circuit breaker or in the grid, due to the magnitude of the arc. Therefore, the cut-off operation and the reliability of the circuit breaker are important in the commercialization of HVDC. In this paper, a current-limiting DC circuit breaker...
In this paper, DC current limiting and interrupting operation of DC circuit breaker using double quench, which consists of DC circuit breaker (DCCB), series resonance circuit, surge arrestor and superconducting elements (SCEs), were analyzed. The suggested DC circuit breaker using double quench of SCEs can per-form twice DC fault current limiting operation in case of larger DC fault current...
Photovoltaic power generation and wind power generation are important renewable energy sources in the present power system. However, since these power generations are interconnected to the power system through power converters, the interconnection of large amount of renewable energy sources leads to lower the power system stability due to the lack of the inertial energy of conventional...
In SMES system, the power conditioning system (PCS) interfaces the superconducting magnet and the AC system. At present, PCS generally adopts PWM converter based on the high-frequency switching devices. The converter outputs PWM pulses voltage with steep rising and falling edges. It is transmitted to the superconducting magnet via the cable, which leads to a spike overvoltage at the...
Applying high-temperature superconducting (HTS) tapes to superconducting magnetic energy storage (SMES) is expected to improve small sized high magnetic field coils. In developing high field coils using HTS tapes, however, large electromagnetic forces caused by a large current and high field can degrade the critical current of HTS in the winding. To decrease the electromagnetic forces, the...
SMES coil constructed of YBCO coated conductor has been researched these years for its advantage of stored energy without loss under operated temperature. However, the flexible corc cable which can wind with small radius and can work under high magnetic field may be a promising option for smes coil for higher stored energy and higher current. Therefore, it is necessary to consider the smes...
We have studied magnetic levitation properties for valuable metals by magneto-Archimedes effect under a high magnetic field gradient. In order to enhance the magnetic force factor BdB/dz in vertical direction, a ferromagnetic cylinder and an array of cylinders were set into the room temperature bore of a 10 T superconducting magnet. We optimized the shape and the arrangement of the...
The Einstein Probe Satellite is a mission of the Chinese Academy of Sciences to explore all-sky transient X-ray sources and constantly various X-ray sources, which is planned for launch around end of 2022[1]. It will carry a Wide-field X-ray Telescope (WXT) with a large instantaneous FoV and a Follow-up X-ray Telescope (FXT) with a large effective area and a narrow field-of-view. It is...
Magnets with good field uniformity in a good-field region (GFR) of a certain volume are of interest for various research and calibration applications. Due to their simplicity and relatively low cost, Helmholtz coils have been the preferred magnet system for such projects. With air cooling, the magnetic flux density possible with Helmholtz coils is limited to typically 1 mT or below, and field...
The high temperature superconductor (HTS) direct current (DC) induction heater shows great advantages on high efficiency and heating quality in comparison to traditional AC induction heater. A commercial megawatt (MW) HTS DC induction heater using REBa2Cu3O7-δ (REBCO) conductors has been developed by Shanghai Jiao Tong University and JIANGXI Lianchuang Opto-eletronic Science and Technology...
Wenjiao Yang, and Guangtong Ma*
With the merits of passive stability, energy-saved and environment-friendly, high-temperature superconductor (HTS) magnetic levitation (Maglev) is regarded as a promising candidate for the future high speed transit. Limited by the experimental conditions, numerical methods are generally employed in most of the current research on dynamic charactristics of high...
Abstract: Superconducting magnet is capable of generating immensely strong magnetic field due to its large carrying-current capacity and low power loss, making it a promising candidate for transportation systems and power systems, such as EDS train, NMR/MRI and SMES. It is well known that the higher magnetic field can bring above systems better properties. However, the increase in local...
Electrodynamic suspension (EDS) train is one of the most important ways to develop high-speed or ultra-high-speed rail transit. In order to explore the dynamic characteristics of EDS system with figure-eight-shaped coil, this paper transforms the complex electromagnetic field coupling relationship between vehicle coils and ground coils into a simplified circuit relationship, and introduces the...
As a promising candidate for future high-speed transportation, the electrodynamic suspension (EDS) train has drawn considerable attention. The dynamic response of EDS train to eternal excitations could make a great difference on its operating performance, especially in high speed range. Thus this paper focuses on the vehicle dynamics of EDS train, which is separated into two subsystems i.e.,...
The superconducting magnetic levitation(Maglev), realized by high-Tc superconductor subject to high magnetic field generated by permanent magnet of NdFeB, has attracted special interests for applications such as transit and superconducting magnetic bearing(SMB). In the last two decades, several prototypes of HTS Maglev or SMB have been proposed and developed by different groups. Furthermore,...
In this work, the two major electrodynamic suspension (EDS) methods for transportation, namely the permanent magnet - metal plate method and the superconducting magnet - null flux ground coil (figure 8 coil) method, are studied analytically and numerically. Numerical models in different scales were built and the performances of levitation force, resistive force, characteristic speed, et al....
An EDS-Maglev system mainly consists two parts: ground null-flux coils and superconducting magnet on a vehicle or sled. This paper forces on the study of the characteristics of the EDS-Maglev system using dynamic circuit theory. A numerical method including 4-order Runge-Kutta method and inductance space criterion was proposed to improve the calculation accuracy. The calculated results were...
In order to develop levitated transportation systems based on coated conductors tapes, it is important to know not only the information on the levitation force at vertical displacement, but also the data on the stability of the system at lateral displacements of the superconductor with respect to permanent magnets. Data on the lateral stability of stacks of CC-tapes above the magnetic rail...
High-temperature superconducting (HTS) maglev train, with the advantages of low-energy consumption, simple mechanical structure and environment-friendly, is an ideal high-speed transportation in the future. HTS maglev dynamical characteristics considering track random irregularity is important, because the track random irregularity is ineluctable due to the defects produced in installing...
Superconducting Maglev is one of the hottest research directions for superconducting applications. The speed of superconducting Maglev on rail is much faster than conventional rail. And hence the superconducting Maglev is considered as a ultimate substitute for rail traffic. The superconducting magnet made by HTS coils is the core component for superconducting Maglev. This paper illustrates a...
High Temperature Superconducting(HTS) magnet has been proved to be a potential candidate for the maglev system because of its stable self-suspension, low energy consumption and adjustable suspension distance. Nowadays studies on levitation force of HTS magnet are mainly carried out in electromagnetic levitation system, which is between YBCO bulks and permanent magnet guideway. In this paper, a...
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INTRODUCTION
Recently, magnetic levitation techniques have been developed for various fields such as magnetically levitated vehicles and energy storage flywheels. Thus, there are many reports about levitation techniques using high critical temperature (Tc) superconducting magnetic bearings (SMBs) composed of superconducting (SC) bulk and permanent magnet (PM). However, there are not so...
Recently, the national interest in transportation logistics is increasing due to the population aging and metropolitanization. And, it is a big issue for ultra-high-speed rail technology to meet a lot of demand in a short period of time. Germany has commercialized a 501 km/h train in Shanghai, China (2004), and the TGV in France is operating at 570 km/h. In addition, Japan is currently...
High-temperature superconducting magnetic levitation (HTS Maglev) system has the intrinsic advantage of self-stabilizing suspension without external control, and has great potential to be a new type of rail transit. The HTS bulks are core component of the the HTS Maglev train. Many experiments show that the levitation performance of superconducting bulks have been significantly improved when...
The levitation force of high temperature superconducting (HTS) bulks can be enhanced by increasing the strength of the external magnetic field. Many researchers have reached this conclusion by doing experiments above a permanent magnet guideway (PMG). However, the experimental results have limitations because the magnetic field above the PMG is relatively low. In order to obtain more...
A high precision superconducting levitation system for gravity measurement has been developed which used the levitation of a superconducting sphere by the magnetic field of two superconducting coils. In order to obtain high stiffness in a suspension system, an electrostatic suspension system is introduced to the superconducting levitation system. The hybrid levitation system is operated in...
The superconducting joint resistance in the superconducting magnetic levitation coil leads to the continuous decrease of the closed-loop current, which causes a weakening of the levitation magnetic field in the gravity measuring device. This magnetic field attenuation will cause the falling of the superconducting sphere used to measure gravity, making the measured data larger than the real...
A device for superconducting gravity measurement with high observing precision and stability is developed. In this device the test mass and spring are in the form of a superconducting sphere and superconducting magnet which is operated in the persistent mode. Once the sphere is levitated in the field generated by the superconducting magnet and the gradient adjusted, the sphere will move...
With the rapid development of rare earth materials, the permanent magnet electrodynamic suspension (PMEDS) technology has met a new development opportunity. This paper presents a study on a special PMEDS system named as an electrodynamic wheel (EDW). In the PMEDS system, an annular Halbach permanent magnet array is designed and rotated above a flat aluminium sheet. We establish a simplified 2D...
The final development and demonstration of the US made low beta quadrupoles for HL-LHC is in full swing. CERN is planning to start the upgrade of Large Hadron Collider during the Long Shutdown III, which is scheduled to start in 2024. The US is planning to contribute to this upgrade by providing the Q1 and Q3 Inner Triplet elements plus other components. The first iteration of the magnet...
After we have developed the 25 T cryogen-free superconducting magnet (25 T-CSM) with a Bi2223 insert, Nb3Sn and NbTi Rutherford outsert coils [1], we are planning two projects on high field cryogen-free superconducting magnets. One is an upgrade of the 25T-CSM to 30 T with replacing the present Bi2223 insert to an REBCO one [2]. The other plan is to build a new high field CSM beyond 30 T. For...
In the EU funded EcoSwing project the world’s first large-size superconducting low-cost and lightweight multi megawatt wind turbine generator was designed, built and tested in a real wind turbine.
In order to realize this generator a technology to produce high quality HTS coils for reliable industrial use was developed and successfully qualified. Due to the high magnetic fields generated...
Abstract— The High Luminosity LHC Project target is to reach an integrated luminosity of the LHC of 3000 fb-1, corresponding to a factor 10 increase in collisions with respect to the current accelerator. One major improvement foreseen is the reduction of the beam size at the collision points. This requires the development of 150 mm single aperture quadrupoles for the interaction regions. These...
The National High Magnetic Field Laboratory (NHMFL) has launched an innovative project to develop a 40 T all-superconducting user magnet. The first year of funding was awarded by the National Science Foundation and the project started in September 2018. Consideration of a 40 T superconducting user magnet set target specifications of a cold bore of 34 mm with a homogeneity of 500 ppm over a 1...
With the high current carrying capacity of second generation superconductors the increase of power density of electrical devices is a main research subject in the field of superconductor’s application. Several studies show a potential reduction in volume and weight of electrical rotating machines, while keeping the rated power output. Especially, compact and more lightweight generators in...
The future high luminosity (Hi-Lumi) upgrade of the Large Hadron Collider (LHC) at CERN will include eight (plus two spares) 8.4 m-long cryostatted cold masses which will be components of the triplets for two LHC insertion regions. Each cold mass will consist of two 4.2 m-long Nb3Sn high gradient quadrupole magnets, designated MQXFA, with aperture 150 mm and operating gradient 132.6 T/m, for a...
After a successful first test of the 32 T superconducting magnet, it was inspected and prepared for commissioning. Here we report on the initial result of reaching 32 T, meeting the specifications and other pertinent observations from the first test. Following is a brief description of the facilities at its permanent location as a user magnet in the expanded NHMFL MilliKelvin building. The...
The development of off-shore wind farms will need to rely on large turbines, ideally over 10 MW, to be economically viable. Therefore, there is a need for cost effective and very reliable drive trains for large wind turbines. The first step in increasing reliability is to not use gearboxes and connect the generator directly to the turbine rotor. The very large torque required leads to very...
The U.S. High-Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP) team is collaborating with CERN in the design and fabrication of the first 4.5 m long MQXFA magnets, a 150 mm aperture high-field Nb3Sn quadrupole magnet that uses the aluminum shell-based bladder-and-key technology. The first two prototype magnets, MQXFAP1 and MQXFAP2, were assembled and tested while the first pre-series...
Following the development of wide bore superconducting magnets using low temperature superconductors (LTS) for integrating ultra-high field high temperature superconductor (HTS) inserts, new applications for this LTS ‘outsert’ technology require higher temporal and mechanical stability. The development of an 18 Tesla, 150mm bore magnet system designed for scanning tunneling microscopy (STM)...
Offshore wind turbines are becoming an integral part of the future large-scale renewable generation initiatives. It is envisioned that to upscale offshore wind turbines in the range of 10+ MW power, superconducting (SC) technologies must be explored. Several partial and fully SC machine designs have been proposed and demonstrated for offshore direct-drive wind turbines. It is theoretically...
In recent years, several Nb3Sn high field magnet prototypes have been designed and tested in preparation for the LHC Luminosity upgrade and also for the potential Future Circular Collider (FCC). We present a Microsoft Excel -based database tool for storing magnet design parameters and the results of the magnet tests. The hierarchical, yet flexible, structure of the relational database allows...
The High Field Magnet Laboratory of Radboud University is constructing a 45 T hybrid magnet system. The 620 mm bore, 12.3 T, 20 kA, Nb3Sn cable-in-conduit superconducting outsert magnet has been developed and fabricated in close cooperation with the National High Magnetic Field Laboratory in Tallahassee FL. A 22 MW/40 kA resistive insert magnet will contribute another 32.7 T to the total...
One promising source of clean and efficient energy comes from the ocean waves since they transport a considerable amount of energy. In the recent years there have been many highly scientific proposals for harvesting this energy in an efficient manner but in any case one of the key points to guarantee such efficiency is the selection of the PTO (Power Take Off). This conversion process is...
The design of Nb3Sn superconducting magnets for particle accelerators requires the evaluation of the loads applied to the conductor. It was in fact clearly shown by numerous experiments that the loads applied to Nb3Sn conducting elements can reduce their critical current, potentially compromising the magnet performances. This reduction can be reversible or not....
The Grenoble Hybrid magnet is a modular platform applying resistive and superconducting technologies to deliver various continuous high magnetic field and flux configurations. They range from 43 T in 34 mm diameter with 24 MW down to 9 T in 800 mm with the superconducting coil alone. The key design parameters are recalled including the specifically developed conductor, the large bore...
Abstract:
Trapped magnetic flux by high temperature superconducting tape stacks manufactured by ASCG at University of Cambridge allowed to reach the current world record of 17.7 T [1]. Despite of this undisputed success there are different challenges for such tape-stacks to operate in field cooled DC conditions [1], pulse conditions [2] as well as AC conditions, where demagnetization of...
Brookhaven National Lab (BNL) is in the process of building a 25 Tesla, 100 mm cold bore HTS solenoid for the Institute of Basic Science (IBS) in South Korea for their search for Dark Matter Axions. The magnet consists of 28 coils (in a 14 double-pancake (DP) coils configuration) with an inner diameter of 105 mm and has an outer diameter of 200 mm, wound using Second Generation (2G) High...
A 10-Mvar HTS synchronous condenser is under development, including a 36-slot air-core stator, and a 4-pole HTS rotor assembled by 12 REBCO double pancake (DP) coils. In this work, a scaled superconducting magnet prototype consisting of two DP coils was designed and fabricated before full manufacturing, which has an effective length of 300 mm and was wound by 5-mm wide REBCO tapes. To avoid...
Developments in 2G HTS conductor performance continue to drive the design and operating limits for a broad range of demanding magnet applications. The design, testing and fabrication technology of 2G HTS (RE)BCO conductors is presented, highlighting the ability of 2G HTS wire to function under a wide range of operating conditions. SuperPower continues to address 2G HTS conductor development...
The application of high temperature superconductors (HTS) for the generation of high magnetic field is still limited by technical issues like quench detection. The recently developed quench detection technique based on Rayleigh backscattering interrogated optical fibers (RIOF) has shown to provide unprecedented levels of detection and advantages over conventional, voltage-based approaches. In...
We present the NbTi magnet system that is currently being constructed at the University of Twente for the demonstration of superconducting Magnetic Density Separation (MDS) . MDS is a new recycling technology that allows to separate non-magnetic waste materials based on their mass density, by combining a ferrofluid with a vertical magnetic field gradient.
The major challenge in the design of...
In 2018 SuperOx Japan reached production capacity of 200 km of 4 mm 2G HTS wires per year. The manufacturing of our standard 2G HTS wires was aimed at the needs of light-weight cables and superconducting fault current limiting devices (SFCL), which operate under the conditions of self-field and 70-77K. Although the standard SuperOx wires with Ic>500A for 12 mm width outperformed the needs of...
Future spaceborne spectrometers for astroparticle detection need high bending power therefore, the use of superconducting magnets is the sole applicable solution. Space magnets require high reliability that, in turn, requires high stability. Avoiding liquid helium cryogenics is also an attractive feature. The use of high temperature superconductors (HTS) or magnesium diboride (MgB2) combines...
Magnet applications require coated conductors with high in-field performance, well-defined geometry, high mechanical stability, as well as adequate stabilization. At THEVA coated conductors are produced using an all PVD approach. The high performance of the tape is enabled by ISD-MgO buffer layers and several micro meter thick GdBCO HTS layers.
High performance at fields up to 31 T was...
An innovative high-field superconducting magnet of Canted-Cosine-Theta (CCT) type has been proposed for Future Circular Collider (FCC) 16-T dipole magnet design. The unique mechanical structure intercepts the accumulated forces lowering the stress on the windings: intrinsic stress management in high-field Nb3Sn accelerator magnets. Nevertheless, the former itself also becomes a barrier for...
A superconducting induction heater has been developed and commercialized as a high efficient preheater for the Aluminum, aluminum brass and stainless steel extrusion in Korea. Also, Supercoil had a first step for the commercialization of the SIH using MgB2 magnets in Korea. He created the ‘MAGHEET’ as the brand name of the induction heater using magnets such as HTS (high temperature...
Through a combination of thick films (4-5 µm) and a high density (8000 – 12000/µm^2) of fine nanocolumnar defects, excellent critical currents have been achieved in REBCO tapes over a wide temperature range of 4.2K – 65K and magnetic fields of 1.5T – 30T. Record-high engineering current density (Je) of 5200A/mm^2 at 4.2K, 15T (corresponding critical current density (Jc) of 10MA/cm^2) which is...
HTS (High Temperature Superconductor) tapes such as REBCO (Rare Earth Barium Copper Oxide) are very attractive for various industrial applications of magnets and power-cables, especially for high field, high current superconducting magnets. An implementation of a sensitive quench detection for HTS devices is ungently desired for a safe operation, since normal zone propagations of a HTS...
Electrical energy storage devices are critical components of electric power systems of every aerospace vehicle. They are needed for many functions, such as an electrical accumulator unit (EAU) to handle transient loads both on/off the buses, for emergency power during system failure, to provide high-power for pulsed loads, and as an energy source for electric-vehicle (EV) propulsion....
ReBCO CC (Rare earth barium copper oxide coated conductor) is a viable candidate as a conductor for future high-field magnets due to its mechanical strength, high Tc, and favorable Jc vs. B dependence. In practice, some ReBCO coils, especially solenoids, only utilize a fraction of the full critical current throughout the winding due to the large (5-7) anisotropy of Ic, thereby developing...
CERN launched a high-field magnet R&D program aimed at demonstrating 16 T class superconducting magnets for future circular colliders. The program includes designing, manufacturing, and testing two Nb3Sn magnet models, namely the Enhanced Racetrack Model Coil (ERMC) and the Racetrack Model Magnet (RMM). Both magnets target a magnetic field of 16 T with 10% margin on the load line at 4.2 K. The...
We have proposed a novel superconducting electric power system with energy storage function. This system will overcome the obstacles for future large-scale utilization of renewable energies by compensating their output power fluctuation. In particular, the potential of a long solenoid coil as a superconducting cable with energy storage function has been investigated in this study. This means...
Advanced Conductor Technologies is developing high-temperature superconducting (HTS) Conductor on Round Core (CORC®) cables and wires for high-field accelerator, fusion and scientific magnets. One of the concerns with operating any HTS conductor in magnets that operate at currents exceeding 10,000 A at fields of over 20 T in future accelerator magnets, or 50,000 A at fields over 12 T in fusion...
The resistive type superconducting fault current limiter (SFCL) is suggested to suppress the surge current in voltage sourced converter based HVDC (VSC-HVDC) power systems. The general design scheme of 40 kV/2 kA resistive DC SFCL is discussed firstly. Furthermore the electromagnetic analysis and structure design of the current limiting element are performed in emphasis. In order to study the...
ABSTRACT BODY:
HTS tapes, because of their widths and large shape aspect ratios, have not been readily manufacturable into Rutherford or Roebel cables, even though these kinds of cables are required for many large coil applications. A type of transposed Roebel cable is under development with 2G tape, but its design flexibility is very limited, and its processing very complex, as well as...
In this paper, quench simulations on the High-Luminosity Large Hadron Collider (HL-LHC) MCBRD canted-cosine-theta (CCT) magnets are compared to experimental observations on the MCBRD short models and prototypes. These magnets feature insulated NbTi/Cu strands wound in aluminium formers, where two concentric coils held in place by the formers produce a dipole field over the bore.
The magnet...
Within a collaboration of Jiangsu Zhongtian and Beijing Jiaotong University, one phase of resistive type superconducting fault current limiter (SFCL) for the 220kV transmission voltage level has been designed and manufactured. The active part of the SFCL consists of 128 bifilar coils made of 12mm wide steel-stabilized YBCO conductor supplied by Shanghai Superconductor, and is housed in a...
The HTS (high temperature superconductor) cable is an important component of large magnet system due to its excellent electromagnetic characteristics. The contact mechanical properties such as friction and contact resistance are significantly affected by the contact force among the HTS tapes in HTS cable when subjected to the strong magnetic field, high current, and low temperature in extreme...
The high-luminosity LHC upgrade (HL-LHC) aims to increase integrated luminosity by a factor of ten compared to the present LHC. To focus the beam more strongly towards the interaction point, superconducting magnets in the insertion regions must be upgraded. In the framework of CERN-KEK collaboration, KEK is in charge of developing a large150-mm-aperture beam separation dipole (MBXF). The field...
We are developing a tabletop 1-GHz microcoil nuclear magnetic resonance (NMR) spectrometer of compact, low-cost, and small-footprint features while having better peak resolution and sensitivity than conventional lower field NMR spectrometers, enabled by the high-temperature superconducting (HTS) REBCO no-insulation (NI) magnet. In this paper we present construction and test results of a...
Among various superconducting magnet diagnostics, acoustic techniques are valuable for characterizing mechanical instabilities associated with lengthy training, premature quenching and other performance limitations. While acoustic emissions from magnets were studied since early 80s, techniques involving external acoustic excitation have so far been of limited use. As such techniques are...
In the frame of the high-luminosity upgrade project (HL-LHC) of CERN for the Large Hadron Collider (LHC), a new double aperture beam orbit corrector magnets will be installed near the recombination dipole (D2). These 2.2 m long NbTi dipoles are built with the “canted cosine theta” (CCT) technique. The two independently powered apertures are oriented such that their field vectors are...
Abstract:
We have been developing a compact 1 GHz (23.5 T)-class LTS/HTS NMR magnet. There were two options of HTS inner coils, i.e. Bi-2223 or REBCO, and we decided to employ the Ni alloy-reinforced Bi-2223 conductors for the inner coils considering a smaller screening current-induced magnetic field of a Bi-2223 coil and its lower risk of unexpected degradation under high fields. The...
The first prototype of the short orbit corrector MCBXFB for the upgrade of the LHC has been fabricated at CIEMAT, in collaboration with CERN, in the framework of the HL-LHC project. It consists of two nested dipoles, with an aperture of 150 mm and physical length of 1.5 m.
A first cold test was performed without the outer dipole coils, which were replaced by a support structure to align the...
Since 2014, an R&D program has been conducted to design, construct, and operate a 400 MHz 66 mm room-temperature bore all-REBCO magnet for high resolution NMR application. It is a collaborative program led by the Korea Basic Science Institute (KBSI) in participation of the Korea Institute of Machinery and Materials, Kunsan National University, National High Magnetic Field Laboratory, Seoul...
Superconducting magnets include various electrically-insulated metallic parts. The stray capacitance between these elements can be monitored and utilized to acquire information about the magnet condition and behaviour.
It is well known that dedicated capacitive sensors can be used to monitor the local strain. Furthermore, it was recently proposed to use a stray-capacitance monitoring system...
For the HL-LHC project, a 90 mm double aperture NbTi quadrupole magnet is being developed as an option to replace the 70 mm aperture LHC quadrupole MQY. This cos(2theta) magnet has an operating gradient of 120 T/m at 1.9 K and a magnetic length of 3.67 m. A single aperture short model magnet with a magnetic length of 1.2 m at 1.9 K has been designed at CEA and is being manufactured in...
With the increase of the magnetic field of NMR, the traditional LTS materials cannot meet the requirements of ultrahigh field NMR magnet design. In recent years, with the development of high-temperature superconducting tapes (especially ReBCO tapes), hybrid magnets with HTS magnets as interpolating magnets have become an important choice for designing ultrahigh field NMR magnets....
It is relevant to establish a reliable coil winding techniques which is free from local defects and/or delamination of REBCO tape strand. A coil is usually tested by measuring transport current-voltage characteristics as a whole, however, the position and distribution of the defects can not be identified from such global measurements. This prevent us from clarifying the mechanism of the...
The new and unique accelerator complex FAIR is currently under construction at GSI, Darmstadt, Germany. FAIR, the Facility for Antiproton and Ion Research, will investigate matter behavior inside stars, antimatter as well as biophysics questions using its variety of physics experiments. The core of this facility is the 1100 m circumference heavy ion synchrotron SIS100 featuring 100 T/m...
We are developing a superconducting isochronous cyclotron for proton therapy. Its yoke weight is about 65 tons, which is less than one third of our normal-conducting 230 MeV cyclotron.The sprit pair superconducting coils using NbTi wire are conduction-cooled by four 4 K Gifford-McMahon cryocoolers. Pure iron magnetic poles have deep valleys and four sectors with higher spiral angles than 60...
This paper presents a method to mitigate screening current by manipulating temperature in a high temperature superconductor (HTS) pancake coil. Named as “Thermal Eraser”, it utilizes an electric heater that is optimally designed to “create” a target temperature profile in the HTS pancake coil. The key idea is to control field and temperature dependent critical current Ic (B,T) of “individual”...
A new international facility for antiproton and ion research (FAIR) is currently under construction in Darmstadt, Germany. The SIS100 heavy ion synchrotron, with a magnetic rigidity of 100 Tm, will provide the high intensity primary beam required for different research experiments. The synchrotron is composed of 415 fast cycling superconducting magnets from which 108 are dipole magnets. The...
A curved superconducting magnet for proton therapy was built and tested by the Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL). This magnet consists of two Canted-Cosine-Theta (CCT) dipole layers with a clear bore diameter of 290 mm, bend radius of 0.9 m, and magnetic bend angle of 50 degrees. The magnet design will be discussed in the context of a reduced bend...
Conduction-cooled magnets are gaining popularity as Helium reserves diminish. High-temperature superconductors, such as YBCO, can theoretically deliver ultra-high, > 20 T, magnetic field while cooled by an inexpensive and efficient single-stage GM cryocooler. At 20 K common materials still maintain high thermal conductivity, which ensures fast cooldown and fast recovery of a magnet after...
The Jefferson Lab Electron Ion Collider (JLEIC) is a proposed new machine for nuclear physics research. It uses the existing CEBAF accelerator as a full energy injector to deliver 3 to 11 GeV electrons into a new electron collider ring. An all new ion accelerator and collider complex will deliver up to 200 GeV protons. The machine has luminosity goals of 10^34 cm^-2 sec^-1. The whole...
Hadron and proton therapy are cutting edge techniques for cancer treatment and a great development of specialized medical centers and research facilities is foreseen in the next decades. One of the main obstacles to the penetration of the use of charged particles for therapy is the construction of complex and expensive accelerating structures and rotating transfer lines, i.e. gantries, able to...
The U.S. Magnet Development Program is developing Canted-Cosine-Theta (CCT) magnet technology for future high field accelerator magnets. The CCT concept prevents Lorentz force accumulation by placing turns within precision-machined grooves that are separated by ribs and a spar that intercept forces, substantially reducing the stress in the conductor. CCT technology has been advanced through...
Provided that a cyclotron system requires DC magnetic field, the no-insulation (NI) HTS magnet may be a good candidate as it may enable the cyclotron magnet to be more compact and reliable, yet generate a substantially higher magnetic field than its insulated counterpart. Here we report on a design study of a NI HTS cyclotron magnet for acceleration of carbon ions under isochronous condition...
In the previous systematic research on short models of round CORC-like cables the range of design parameters like the core diameter, lay angle, pulling force etc. have been identified that should be respected in long-length cable production. Based on this knowledge we have manufactured 40 m long cable with two layers each comprising four Furukawa-SuperPower tapes 4 mm wide. Tapes are laid in...
Development of superconducting undulator (SCU) technology continues at the Advanced Photon Source (APS). Recently, a new helical SCU has been added to the portfolio of two planar SCUs operating at the APS. The concept of a novel Superconducting Arbitrarily Polarizing Emitter, or SCAPE, has been suggested and tested in a prototype. Work on a long SCU which combines two up to 1.9-m long planar...
QST, as Japan Domestic Agency in ITER, has responsibility to procure 9 ITER Toroidal Field (TF) coils and all 19 TF Coil Cases (CC). The 9 TF coils are procured by two suppliers to ac-celerate their production. The series production of Double-Pancakes (DPs) and Winding Pack (WP) are in progress in both two manufacturing lines. 1st WP have been completed and net three WPs are in fabrication....
It was a milestone to generate a record-high DC field of 45.5 T by use of a 14.4 T no-insulation (NI) REBCO insert, named Little Big Coil (LBC), operated in a 31.1 T resistive background magnet by the National High Magnetic Field Laboratory. The engineering current density of the NI REBCO insert was ~1200 A/mm2 at 45.5 T, nearly 6 times larger than that of the conventional insulated HTS coils,...
INFN is developing at LASA lab (Milano, Italy) the prototypes of five corrector magnets, from skew quadrupole to dodecapole, which will equip the high-luminosity interaction regions of the High Luminosity-LHC (HL-LHC). These magnets are based on a superferric design, which allows a relatively simple, modular and easy to construct magnet. This activity takes place within the framework of a...
We aim to develop a persistent-mode 1.3 GHz (30.5 T) NMR magnet with a REBCO layer-wound (LW) insert, a Bi-2223 LW midsert and LTS LW outsert. Protection of the REBCO insert is of great importance and we have employed intra-layer no-insulation (LNI) method in a magnet design [1],[2]. In the present work, we developed a model magnet similar to the 1.3 GHz NMR magnet, i.e. REBCO/Bi-2223/LTS...
The photon beam brightness of synchrotron light facilities is increased by reducing the beam emittance. For the upgrade of the storage ring of the Swiss Light Source (SLS2), the lattice achieving a low emittance foresees longitudinal gradient bending (LGB) magnets producing high peak field values and quasi-hyperbolic field profiles to minimize emittance at locations of radiation.
Two types of...
The plasma confinement of the International Tokamak Experimental Rector (ITER) is provided by the magnetic field generated by 18 toroidal filed coils (TFC). Fusion for Energy, the European Domestic Agency for ITER, is responsible for the supply of 10 TFC to ITER project.
Their procurement has been divided in three main work packages: I) the production of the radial plates, structural stainless...
In a REBCO no-insulation (NI) magnet coil, the turn-to-turn contact resistance (Rc) determines the coil’s quench self-protection ability, charging delay time and the energy loss during field ramp. Therefore it is critical to control Rc to suitable values. In our previous investigation, we measured Rc at 77 K and 4.2 K under various contact pressures and pressure cycles, and studied the effect...
Future accelerator magnets for producing 20 T and beyond will require using high temperature superconductors (HTS) in combination with low temperature superconductors (LTS). Under the U.S. Magnet development Program (US-MDP), LBNL is exploring the possibility of fabricating HTS insert dipoles based on Bi-2212 conductors, using the Canted-Cosine-Theta (CCT) technology, in order to increase the...
The first ITER’s European Toroidal Field Coil (TFC) is going to be assembled in 2019. The TFC is composed mainly by the superconducting Winding Pack (WP - manufactured in Europe), and the Coil Cases (TFCC - manufactured in Japan), which provide structural integrity to the magnet and offer interface connections with the rest of the machine.
Dimensional measurements and other manufacturing...
Because nowadays high temperature superconductors (HTS) can carry very strong currents under a high strength magnetic induction at a low temperature, the generation of continuous magnetic fields in the 25 to 50 T range, unattainable with conventional superconductors, is becoming reality.
However, HTS magnets must be effectively protected against transition to the normal state (quench),...
The Central Solenoid (CS) is a key element of the ITER Magnet system, including six identical coils, called modules, assembled together to form a 4 m outer diameter, 13 m high solenoid. It is a superconducting magnet, using a 45 kA Nb3Sn conductor internally cooled by circulation of supercritical helium at 4.5 K with a peak field up to 13 T. It is enclosed inside a structure providing...
High temperature superconductor (HTS) no-insulation (NI) coil is widely applied on high field magnets. In a multiple coil system, the quench behaviour of one coil is considerably affected by other coils through electromagnetic coupling. Meanwhile, quench on one coil can induce a current and fields changing on other coils, which may leads to eddy loss and mechanical degradation on these coils....
Nb3Sn accelerator magnets are poised to play a key role at improving the luminosity of the Large Hadron Collider (LHC) at CERN by a factor of 5-10, significantly improving its potential for exploring physics beyond the standard model of particle physics. Nb3Sn porotype magnets, based on cosine-theta design, consistently need 10-25 quenches to achieve their best performance whereas a new...
The development of ambitious REBCO HTS coils (Rare-EarthBiCaCuO High Temperature Superconductor) is faced by two commonly acknowledged issues: Protection against thermal runaway induced by local dissipative zones, and dynamic field homogeneity. These two problems stem from two specificities of REBCO Coated Conductors: significant spatial inhomogeneity of critical current density and large...
Training is a long-standing problem hindering performance of high-field superconducting accelerator magnets. Proliferation of cracks in the epoxy impregnation and mechanical motion of the conductor in a stick-slip fashion are known to be the most common factors causing premature magnet quenching, and are also responsible for the training. Identifying and understanding those processes is thus...
The 32 T all-superconducting magnet of the National High Magnetic Field Laboratory was successfully tested in December 2017 and it is expected to be available for users in 2019. This all-superconducting magnet, comprised of two HTS inner coils and five outer LTS coils, is the first superconducting magnet above 30 T and some 8 T beyond the current strongest superconducting magnet in use as a...
The screening current in REBCO coils has been proved to have an important impact on the field quality, which is critical for applications with high field homogeneity requirement, such as MRI and NMR. As demonstrated in ‘Little Big Coil’ experiments by NHMFL, the screening current in REBCO coils may also have a huge influence on its strain distribution, especially for high-field operations. A...
MIT and Commonwealth Fusion Systems (CFS), a new startup company focused on the rapid commercialization of fusion, are jointly pursuing a privately-funded, accelerated approach to demonstrate the feasibility of fusion energy. The CFS/MIT team is currently developing a new generation of high-field, large-bore, REBCO-based superconducting magnets to incorporate into a compact net-energy tokamak...
