HYSTERESIS AND EDDY-CURRENT LOSSES OF AG SHEATHED (BI,PB)(2)SR2CA2CU3OX ROD-FORM WIRES UNDER AC TRANSPORT CURRENTS

The AC losses at 77 K are investigated on the Ag sheathed (Bi,Pb)(2)Sr2Ca2Cu3Ox rod-form wires under AC transport currents in self-fields. The AC losses for the samples are expressed as a sum of the hysteresis loss P-h and the eddy-current loss P-e. Both contributions are derived from a conventional fitting procedure and show fairly good agreements with the theoretical predictions. The AC losses are nearly independent of the thickness of the Ag sheath for the sample when P-c < P-h, while showing a gradual increase with the thickness when P-e > P-h. The criteria for the thickness of the Ag sheath, which corresponds to P-e approximate to P-h, is determined from operational conditions and actual size factors of the sample.