Superconducting State Stability

Abstract

We present a review of new results concerning the superconducting state stability under nonstationary conditions. We consider the effect of small perturbations of the temperature δT and the electric field δ E. We present a general approach to the problem of superconducting state stability in a multifilamentary composite wire carrying a time—dependent transport current I(t). We derive an equation determining the current-carrying capacity of this wire, i.e., the maximum superconducting current, I _m . We show that I _m depends on the physical properties of the multifilamentary superconducting composite, the geometry of the multifilamentary area, the cooling conditions, and the transport current ramp rate İ. We consider a quench propagation in a multifilamentary composite wire carrying a time—dependent transport current İ and the superconducting state instability on the normal zone propagation velocity v. We present an equation determining v in a multifilamentary composite wire as a function of İ.