Transport and magnetic J_(c) of MgB_(2) strands and small helical coils

摘要

The critical current densities of MgB_(2) monofilamentary strands with and without SiC additions were measured at 4.2 K. Additionally, magnetic J_(c) at B=1 T was measured from 4.2 to 40 K. Various heat treatment times and temperatures were investigated for both short samples and small helical coils. SiC additions were seen to improve high field transport J_(c) at 4.2 K, but improvements were not evident at 1 T at any temperature. Transport results were relatively insensitive to heat treatment times and temperatures for both short samples and coils in the 700-900℃ range.