AC losses of multifilament superconductors at frequencies between 1 and 500 Hz

We report calorimetric measurements of the ac losses of a small superconducting coil wound from a filament superconductor designed for low ac losses (filament φ = 8 μ,number of filaments 1045, CuNi barriers). The coil was pulsed with a maximum dB/dt = 480 kG/s. Further the ac losses were measured, when the coil current consisted of a dc- and a superimposed ac component with
1 \leq f \leq
500 Hz. The modification of the ac losses by the dc component of coil field and coil current was investigated.