On the stability of the critical state with inhomogeneous temperature in composite superconductors

TL;DR

This paper investigates the stability of the critical state in composite superconductors with inhomogeneous temperature distributions, deriving a new integral criterion for thermomagnetic instability that accounts for spatial inhomogeneities.

Contribution

It introduces a novel integral criterion for thermomagnetic instability in inhomogeneous superconductors, extending previous homogeneous models.

Findings

Derived a limit for thermomagnetic instability in inhomogeneous conditions

Established an integral criterion considering the entire superconductor's influence

Showed the criterion differs from homogeneous temperature profile cases

Abstract

The problem of the thermal and magnetic destruction of the critical state in composite superconductors is investigated. The initial distributions of temperature and electromagnetic field are assumed to be essentially inhomogeneous. The limit of the thermomagnetic instability in quasi-stationary approximation is determined. The obtained integral criterion, unlike the analogous criterion for a homogeneous temperature profile, is shown to take into account the influence of any part of the superconductor on the threshold for critical-state instability.