The inductive response of type II superconductors to applied fields with trapezoidal time dependence is described for samples with a slab geometry. An extension of the critical state model which accounts for the observed waveform of the voltage, induced in the pick-up coil, is given. Typical experiments on Nb-slabs with weak pinning and flux flow in fields with both small and large amplitudes are reported.
van de Klundert, L. J. M., Gijsbertse, E. A., & van de Braak, H. P. (1978). The response of type H superconductors to trapezoidal magnetic fields. Physica B+C, 94(1), 41-52. https://doi.org/10.1016/0378-4363(78)90072-4