Vortex avalanches and magnetic flux fragmentation in superconductors - art. no. 067003

We report the results of numerical simulations of nonisothermal dendritic f lux penetration in type-II superconductors. We propose a generic mechanism of dynamic branching of a propagating hot spot of a flux flow/normal state triggered by a local heat pulse. The branching occurs when the flux hot spo t reflects from inhomogeneities or the boundary on which magnetization curr ents either vanish, or change direction. The hot spot then undergoes a casc ade of successive splittings, giving rise to a dissipative dendritic-type f lux structure. This dynamic state eventually cools down, turning into a fro zen multifilamentary pattern of magnetization currents.