Transient flux flow voltages in type II superconductors

Transient flux flow voltage are observed when constant current is switched on in a type II superconductor at low magnetic fields. The nature of the transients is related to the method of formation of the flux line lattice. The transients are attributed to changes which occur in the flux line lattice as inhomogeneities created at the time of formation of the lattice move out of the sample as a result of flux flow. A model is developed to describe this process which includes the requirement that when dissimilar regions of flux move across the sample, the rate of flow must be the same for these regions, so that an equipotential exists across the sample width. For currents below the equilibrium critical current, excellent fits to this model are obtained for our data