A 9-tape, 14 mm wide ReBCO Roebel cable was soldered onto a U-shaped holder. Ic was determined at 4.2 K with applied fields up to 12 T. At varying I/Ic, different heat pulses resulted in different quench behaviors. For a given sample, these different behaviors were used to construct a stability diagram. Stability diagrams were constructed for samples with different levels of insulation.
We have investigated the relationship between local critical current distribution and global current capacity of multi-filamentary RE-123 coated conductor (CC). RE-123 CCs have critical issues on (1) spatial inhomogeneity in local critical current distribution which would become an origin of local burnout of a magnet coil and on (2) magnetization current which affects the spatial and temporal...
Operating current of large-scale superconducting magnets needs to be enhanced up to several thousand to several tens thousand amps from the viewpoint of magnet protection in relation to the consumption of stored energy by an external resistor. On the other hand, superconducting magnets for MRI need the uniformity of produced magnetic field within ppm order in time and space. We proposed the...
ITER project has been running in decades and has started after complications. While it is now under construction, design activity for new fusion device called “DEMO” has already taken place, in which the superconducting magnet system will be much larger than that of ITER. In the present project, the magnets are made of Nb3Sn superconducting material, hence heat treatment is needed to generate...
Karlsruhe Institute of Technology (KIT) developed the HTS Cross Conductor (CroCo), a round twisted stacked REBCO strand with outer Cu envelope, optimized for high current density and easy long length fabrication. First generation of HTS CroCos were built from 6 mm and 4 mm wide REBCO tapes with critical currents Ic ~ 3 kA (77 K / s.f.) and Ic > 8 kA (4.2 K, 12 T). Due to the continuously...
In the superconducting applications for large current and strong magnetic field, a twist structure between superconducting wires can prevent generation of loop current and reduce AC loss. However, the twist structure is difficult to achieve for high temperature superconducting (HTS) tapes because of their high width-thickness ratio. In order to apply twist process more easily, a novel...
AC loss of the superconducting composite conductor is one of the important factors for the application of superconducting power devices since it determines the stability and operation cost. In recent years, a variety of models have been successfully developed to simulate HTS coated conductors (CCs), while the calculation of AC loss focused on superconducting strands based on REBCO CCs is...
Cable-in-conduit (CIC) conductors made of Nb3Sn wires have been developed for use in large high-field magnets. A "wind, react and transfer" method has been established to avoid the degradation by excess strain after reaction of Nb3Sn and to adopt organic insulator. However, the "react and wind" method is preferred for a helical coil for a helical fusion reactor, because the "transfer" process...
A finite element method was developed to investigate the strain distribution of REBCO coated conductors under bending conditions relevant to high-field accelerator magnets. Due to their high current and high field capabilities, REBCO tapes are promising conductors for high field magnet applications. During magnet fabrication, REBCO tapes bend around a former. Because of the asymmetric...
ENEA, in collaboration with CRIOTEC Impianti S.r.l. and TRATOS Cavi S.p.A. (the three associated members of the Italian Consortium for Applied Superconductivity, ICAS) has manufactured approximately 100 km of Cable-in-Conduit-Conductors (CICCs) in the last decade, mainly for fusion tokamak, but also for different applications such as magnets for testing facilities. This production includes a...
High temperature superconducting (HTS) device is a new application of superconducting technology in power system. In real utility, HTS device expose to environment where there exists many problems, such as crushing stress, bending stress, background magnetic field and so on. To ensure the safety of the HTS device, it is necessary to study the stability behaviors of HTS tapes. In addition,...
The CFETR, “China Fusion Engineering Test Reactor”, is a new tokamak device. Its magnet system includes the Toroidal Field (TF), Central Solenoid (CS) and Poloidal Field (PF) coils. The main goal of this project is to build a fusion engineering tokamak reactor with fusion power of 50-200 MW and self-sufficiency by blanket. The maximum field of CS and TF will get around 15 T, which is much...
A prototype conductor for Fusion magnets rated for about 60 kA at 5K, 12 T has been fabricated. The conductor is composed by a flat cable in a steel conduit; the flat cable consists of twisted and soldered stack of tapes in round copper profiles which are cabled around a flat central former. Initially the performances of the coated conductor tapes used for the cable manufacturing were fully...
