Title :
The VAMAS intercomparison on the upper critical field measurement in Nb-Ti wire
Author :
Tachikawa, K. ; Koyama, S. ; Takahashi, S. ; Itoh, K.
Author_Institution :
Fac. of Eng., Tokai Univ., Kanagawa, Japan
fDate :
6/1/1995 12:00:00 AM
Abstract :
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.<>
Keywords :
critical current density (superconductivity); electric current measurement; magnetic field measurement; niobium alloys; superconducting cables; superconducting device testing; titanium alloys; NIST-SRM 1457; Nb-Ti; Nb-Ti wire; VAMAS H(c2) intercomparison; VAMAS TWA 6 activity; Versailles Project on Advanced Materials and Standards; anisotropy; coiled specimen; critical current measurement; high field measurement; high magnetic fields; homogeneity; scatter coefficient; upper critical field measurement; Critical current; Current measurement; Laboratories; Loss measurement; Magnetic field measurement; Performance evaluation; Scattering; Standardization; Superconducting materials; Wire;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
