The self fied effect on the power-law index of superconducting cables

TL;DR

This paper investigates how the self-field effect influences the power-law index and critical current derivatives in superconducting cables, revealing a compensation effect that equalizes strand limits.

Contribution

It demonstrates that self-field effects increase the power-law index and decrease critical current derivatives, and shows the strand take-off limit remains unchanged due to a compensation effect.

Findings

Self-field effect increases the power-law index.

Self-field effect decreases the magnetic field derivative of critical current.

Strand take-off limit remains equal to that of a free strand.

Abstract

It is shown that in the absence of inter-strand current redistribution the self-field effect is to always increase the power-law index of the volt-ampere characteristic and to decrease the temperature and magnetic field derivatives of the critical current line. We show that the take-off limit of a strand in a cable made of insulated strands is equal to that of a free strand due to a compensation effect between the increase of the power-law index and the decrease of the magnetic field derivative of the critical current.