ABSTRACT
This chapter is concerned with the stability criteria against flux jumping under the adiabatic condition. If a high-field superconducting material is exposed to a magnetic field, the field inside the superconductor will stay zero except in a layer adjacent to the surface in which shielding supercurrents are induced. The flux jumping is well understood and stable conductors may be designed under all practical conditions of operation. The chapter shows that two properties inherent in high-field superconductors cause the magnetic instability: flux motion within the superconductor generates heat, and critical current densities fall with increasing temperature. In tape conductors, the size of the superconductor is reduced only in one dimension. Although twisting is fully effective for applied field, it is totally ineffective with respect to the self-field produced by the transport current supplied to the composite. The multifilamentary composite conductor based on the criteria of adiabatic stability and dynamic stability is stable against flux jumping.
