Electric Field and Losses in BSCCO-2223/Ag Tapes Carrying AC Transport Current

Electric field and losses in single layer coils wound of 0.75 m long multifilamentary BSCCO-2223/Ag tapes carrying ac transport current have been studied at both 4.2 K and 77 K in the frequency range from 0.01 Hz up to 100 Hz with the main effort to 50 Hz. Current amplitudes IP were ranging from i=Ip/Ic=0.5 to 1.3, critical current IC determined by the standard 1 µV/cm static electric field criterion. IC of Coil 1 was 15 A at 4.2 K and 3 A at 77 K. Losses due to the wide resistive transition of the coils were found to dominate over self-field losses even well below i=1. Therefore the total losses in the whole applicable i range could not be described well by equations based on the critical state model.