REPORT ON THE 2ND VAMAS AC LOSS ROUND-ROBIN - MAGNETIZATION MEASUREMENT OF LOW-FREQUENCY HYSTERETIC LOSS

We report on the results of the 2(nd) VAMAS intercomparison program on low-frequency (hysteretic) AC loss measurements. Two sets of multifil amentary NbTi strands were subjected to round-robin testing. In an ini tial series of tests, samples in various forms were measured mostly by vibrating-sample- and SQUID magnetometry. Considerable scatter was no ted especially in the small-filament-diameter AC loss data. In a study of measurement accuracy, a supplementary round-robin compared the res ults of VSM measurement of a given pair of copper-matrix samples, In t he light of all the results, factors contributing to AC loss error are discussed and recommendations are made concerning the specification o f future round-robin AC-loss testing.