Measurement of ac losses in multifilament super-conducting wires at frequencies between 1 and 100 Hz

Abstract

Calorimetric measurements of the losses of a superconducting coil wound from a moderately twisted multifilamentary superconducting wire have been made with a coil current consisting of a direct current and a superimposed ac component at frequencies between 1 and 100 Hz. There exists a frequency range where the loss per cycle decreases with increasing frequency. Magnetization measurements on a sample of the multi-filament wire in an applied inductance B = B s + B 0 sin ω t confirmed the results of the calorimetric measurements and indicated that with increasing frequency the flow of magnetic flux into and out of the composite during a cycle becomes more and more diminished.