The VAMAS intercomparison on the upper critical field measurement in Nb-Ti wire

The intercomparison on the upper critical field measurement in the Nb-Ti wire (NIST-SRM 1457) has been performed through the VAMAS (Versailles Project on Advanced Materials and Standards) TWA 6 activity. The homogeneity in the H/sub c2/ of the wire is fairly good, while the coefficient of scatter in the H/sub c2/ intercomparison is about 0.60%. The scatter in high field measurement may cause that in critical current measurement at high magnetic fields. Effects of several factors on the H/sub c2/ of the Nb-Ti wire have also been studied. The coiled specimen shows slightly lower H/sub c2/ than the straight sample. The H/sub c2/ of the wire shows an appreciable anisotropy with respect to the direction of applied field.<
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