AC Losses in a Slab of a Nonideal Type II Superconductor. I. Losses in a Small AC Magnetic Field of a Trapezoidal Wave Form
Abstract
The ac loss in a slab of a nonideal type II superconductor under an ac magnetic field of a trapezoidlike waveform with a small amplitude is discussed with the aid of the criticalstate model including the ohmic current term. It is shown that the analytic expressions of the fluxdistribution derived in this paper show excellent agreements with numerical solutions at frequencies below the characteristic frequency above which the viscousdrag force becomes dominant. The expressions of the frequency dependences of the ac losses are derived from these expressions of the flux distribution. The ac loss increases at first and, then, decreases as the frequency increases. The waveform dependence of the ac loss is also discussed to find the waveform yielding the minimal ac loss.
 Publication:

Japanese Journal of Applied Physics
 Pub Date:
 March 1978
 DOI:
 10.1143/JJAP.17.551
 Bibcode:
 1978JaJAP..17..551K
 Keywords:

 Alternating Current;
 Energy Dissipation;
 Magnetic Fields;
 Slabs;
 Superconductors;
 Waveforms;
 Hysteresis;
 Magnetic Flux;
 Mathematical Models;
 Ohmic Dissipation;
 Viscous Drag;
 SolidState Physics