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

TL;DR

This paper investigates how inhomogeneous temperature profiles affect the stability of the critical state in composite superconductors, deriving a new integral criterion for thermomagnetic instability that accounts for inhomogeneity.

Contribution

It introduces a novel integral criterion for thermomagnetic instability considering inhomogeneous temperature distributions in superconductors.

Findings

The criterion accounts for the influence of any superconductor region on instability thresholds.

Inhomogeneous temperature profiles significantly alter the stability conditions.

The results improve understanding of critical state destruction in real-world composite superconductors.

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.