The coils of high field Nb3Sn magnets are submitted to large loads during assembly at ambient temperature and during operation at cold. This study addresses the characterization of the stress distribution on reacted and impregnated Nb3Sn Rutherford cables under transverse compression, at ambient temperature, in a similar configuration as seen during magnet assembly. We performed an...
Degradation of critical current in a high temperature superconducting (HTS) tape under bending conditions had been previously investigated. These investigations were focused on only either bending or torsion. A rotating flux pump is used to study the charging characteristics of HTS synchronous motor. In order to design the rotating flux pump connected in series, the elliptical winding applied...
High temperature superconducting (HTS) conductors are expected to improve small sized high field magnets. However, the mechanical stresses lower the critical current properties of the HTS tapes. The objective of this work is to clarify the relationship between the critical current properties and the total tensile stresses caused by the winding tension during the coil winding process and the...
A multi-scale mechanical model of Rutherford type, low temperature superconducting cable is discussed in this paper.
First, the numerical approach for the mechanical analysis of the cable using bi-metallic description of the strands is presented. The process of the three-dimensional geometrical reconstruction of the cable during operation, up to the scale of the strand, is described. The...
Large hoop stress causes the deterioration of the transport properties of the winding. Therefore, high electromagnetic force tolerance is required for structure of the winding, and at the same time, it is necessary to limit the current density so as not to deteriorate the superconducting characteristic. As this countermeasure, a high strength pancake coil structure called “Yoroi-coil” (Y-based...
MgB2 superconductors are recognized as one of the promising superconducting wires for utilizations in a current MRI magnet. However, a practical consideration remains that the critical current density and critical magnetic field of the MgB2 wire strongly depend on the stress applied by bending the reacted MgB2 wire. Therefore, the investigation of the electrical properties of the reacted MgB2...
As part of the Hi-Luminosity LHC project, a set of Nb3Sn quadrupoles are being developed aiming to enhance the performance of the inner triplets. The new magnets, identified as MQXFA and MQXFB, will share the same cross section with two different lengths, respectively 4.2 m and 7.2 m. During the magnet development, three short models were tested, along with a number of mechanical models,...
Superconducting bulk materials have high trapped magnetic field ability at a temperature lower than the critical temperature. Since superconducting bulk materials are subjected to electromagnetic force during magnetization process, improvements of the mechanical properties are indispensable for the development of high performance bulk materials. However, the mechanical properties of...
RE-Ba-Cu-O (RE: rare earth element or Y) bulk superconductors have promising potential to be used as a strong trapped field magnet (TFM), which ever can trap a field of over 17 T on a Gd-Ba-Cu-O disc bulk reinforced with the shrink-fit steel. Ring-shaped bulk cylinders with a concentric hole are also considered in practical applications, such as nuclear magnetic resonance (NMR) spectrometer...
The first European superconducting Winding Pack (WP) and the first set of Coil Cases (TFCC) for ITER are going to be delivered in 2017. The TFCC are steel structures which provide structural integrity to the WP, contribute to neutron shielding capacity, provide support to operating forces and offer interface connections with the rest of ITER machine. The TFCC assembly is formed by four main...
Nuclear magnetic resonance (NMR) spectrometer with high resolution using superconducting coils is a powerful apparatus to analyze complex molecular structure or to develop new drugs. Recently, a compact and cryogen-free NMR spectrometer with a medium resolution of 200 MHz (4.7 T) has been developed using annular REBaCuO superconducting bulks, in which the NMR spectra of ethanol with a full...
The 2G coated conductor (CC) tapes exhibit greater potential in magnet and coil applications because of their high critical current density, Jc and good mechanical properties along longitudinal direction. Differences in fabrication processes, architecture, and layer materials in REBCO CC tapes produce different mechanical and electromechanical behaviors under magnetic field B, temperature T,...
ABSTRACT: The mechanical characteristics and behaviors of two superconducting magnets with different low temperature superconducting materials and configurations during excitation and quench training processes are investigated experimentally and numerically in the present work. One is a racetrack magnet made of NbTi/Cu with the maximum magnetic field of 4 T. Another is hybrid superconducting...
The superconducting property of Nb3Sn strands is very sensitive to strain. The transverse electromagnetic loading has been considered as a major origin of the degradation of Nb3Sn cable-in-conduit conductor (CICC) due to the periodic local bending. The degradation of each strand due to this bending should be evaluated to calculate the performance of a CICC. Thus, an analytical model considered...
The ITER Poloidal Field (PF) magnet system is composed of six circular coils, consisting of winding packs (WP) made up from a stack of Double Pancakes (DP) wound of NbTi cable-in-conduit superconductor. The largest coil has a diameter of 24 meters, the heaviest weighs 400 tons, and they are designed to produce a total magnetic energy of 4 Giga Joules at a maximum magnetic field of 6 Tesla for...
