An Analysis of Normal Front Propagation in Superconducting Coils under Quench Condition.

A computer code was developed to simulate normal front propagation and the associated transient characteristic behavior of superconducting coils under quench condition. The analysis method considers the normal propagation in both longitudinal and transverse directions by introducing a logical coordinate system. In a logical coordinate system, superconducting coils are assumed to consist of long wires which are divided into finite lengths of elements. Thus, three-dimensional problems can be transformed to one-dimensional problems. In order to examine the capability of the computer program, the quench propagation in solenoid coil systems with epoxy bonded NbTi superconductors has been analyzed. The results showed good correlation of the computed quench time with the experimental data, and the applicability of the code was demonstrated.