1994 Volume 29 Issue 11 Pages 585-592
This paper summarizes the results of the second critical current measurement intercomparison of Nb3Sn wire sample implemented in the framework of VAMAS (Versailles Project on Materials and Standards) and discusses the origins of data scatters reported by the participants. In the second intercomparison, measurement conditions were strictly specified, particularly in terms of sample strain. Sample B used in the first intercomparison was used as a single sample for the second intercomparison. Variation coefficient of critical current at 12T was greatly reduced from 8.0% in the first intercomparison to 2.2%, probably because sample strains were well minimized among laboratories within the variation of 0.03%. Based on the results of critical current measurements on the NbTi sample as well as those of complementary measurements, it was found that, in addition to the sample strain, uncertainty in magnetic field determination and sample homogeneity substantially contributed to the variation coefficients of the critical current in the second intercomparison.
