Current distribution in multifilamentary superconductors and their quench current degradation
Abstract
When the thickness of the saturated region where the current density reaches the mean critical current density is larger than some threshold value, flux jump occurs. In multiplytwisted cables, such as ones for AC use, or in complicated magnet systems, such as ones for fusion devices, multifilamentary superconductors are exposed to the longitudinal magnetic field that is possible to increase the thickness of the saturated region and to degrade the quench current. The current distribution in multifilamentary superconductors is calculated with two models. With the first one, its temporal evolution and axial variation can be calculated. This is also useful to calculate AC losses. In the second model, the influence of the transverse magnetic field and the filament diameter as well as of the longitudinal magnetic field is taken into consideration. With this model, the transport current at the stability limit against the longitudinal magnetic field instability is estimated. The influences of the critical current density, filament diameter and conductor diameter on the stability limit are evaluated.
 Publication:

IEEE Transactions on Magnetics
 Pub Date:
 July 1994
 DOI:
 10.1109/20.305729
 Bibcode:
 1994ITM....30.2277A
 Keywords:

 Current Distribution;
 Electric Current;
 Magnetic Fields;
 Quenching (Cooling);
 Superconducting Magnets;
 Superconductors (Materials);
 Thermal Degradation;
 Transmission Lines;
 Current Density;
 Dynamic Stability;
 Estimating;
 Magnetic Effects;
 Mathematical Models;
 Ohmic Dissipation;
 Electronics and Electrical Engineering