Electromagnetic and calorimetric measurements for AC losses of aYBa2Cu3O7−δ coated conductor with Ni-alloy substrate

Abstract

The AC losses of a rolling-assisted-biaxially-textured-substrate (RABiTS™) processedYBa2Cu3O7−δ (YBCO) coated conductor (Goyal et al 1996 Appl. Supercond. 4 403–27) with Ni-alloysubstrate and Cu stabilizer were measured at 77 K by both calorimetric (CM) andelectromagnetic (EM) methods. In the CM method, improvements in the measurementwere observed when a Cernox temperature sensor was used to measure the temperature riseon the sample instead of a differential thermocouple. The effect of heat transferred fromcurrent leads was taken into account to improve the accuracy of the CM results. In the EMmethod, the magnetization losses of the sample in a perpendicular applied field weremeasured by an in-plane pick-up coil. The calculation of the calibration factorC of the pick-up coil is discussed. Good agreement between AC loss results obtainedfrom the CM and EM methods confirmed the validity of our measurements andcalculations.