AC loss (50-200 Hz) in YBCO conductors with filaments and Cu stabilization

Abstract

AC loss measurements have been made on YBCO coated conductors in externally applied sinusoidal AC fields using the pick‐up coil method. Various arrangements of YBCO coated conductor have been measured at frequencies of 50 Hz, 75 Hz, 100 Hz, 150 Hz, and 200 Hz, with amplitudes ranging from 0 to 140 mT. Three different sets of IBAD‐based YBCO coated conductor were measured: (i) unfilamented conductors with Cu added either on one side only, or on both sides (as well as the edges), (ii) conductors with various numbers of filament, (iii) 4 mm wide conductors. All samples were 4 cm long and untwisted. The per cycle AC loss per unit length of conductor, displayed in the format Q/B (in J/T.m) vs. Bm. enabled separation of the eddy current and hysteretic components of the total loss, after which the results were analyzed and discussed. The resistivity of the interfilamentary connections were characterized and the results compared to expectation.