STABILITY ANALYSIS FOR A COMPOSITE SUPERCONDUCTOR SUBJECTED TO A LINEAR THERMAL DISTURBANCE

The operational stability of a composite tape/film-type superconductor is studied by considering the impact of a thermal disturbance distrib uted along a line. Issues addressed are failure of intrinsic stability , current sharing, Joule heating, and recovery of superconductivity. M athematical models have been developed to describe the phenomena. The conjugate heat diffusion problem for the superconductor and the stabil izer has been solved by the finite-difference method. The effects of c urrent density and stabilizer dimension have been investigated, result ing in the identification of three modes with regard to the operationa l stability of the superconductor: intrinsically stable, recoverably u nstable, and irrecoverably unstable. Numerical data of instability par ameter, convective cooling rate, Joule heating rate, and current shari ng are presented for NbTi superconductors.