The determination of low-field critical current densities from magnetization data for Nb - 25% Zr

Abstract

Magnetization measurements are used to determine low-field critical current densities of superconductors. Analysis is based on a critical state model and takes into account magnetic field discontinuities at the surface of the specimen. The analysis has been applied to cold-drawn Nb - 25% Zr wires which have been subjected to a range of heat treatments. Results are compared with direct measurements of the critical currents of wires.