Report on the second VAMAS AC loss round robin-magnetization measurement of low-frequency hysteretic loss

摘要

We report on the results of the 2nd VAMAS (Versailles Project on Advanced Materials and Standards) intercomparison program on low-frequency (hysteretic) AC loss measurements. Two sets of multifilamentary NbTi strands were subjected to round-robin testing. In an initial series of tests, samples in various forms were measured mostly by vibrating-sample- and SQUID magnetometry. Considerable scatter was noted especially in the small-filament-diameter AC-loss data. In a study of measurement accuracy, a supplementary round-robin compared the results of VSM measurement of a given pair of copper-matrix samples. In the light of all the results, factors contributing to AC loss error are discussed and recommendations are made concerning the specification of future round-robin AC-loss testing.