Vortex Plastic Motion in Twinned Superconductors.

We present simulations, without electrodynamical assumptions, of {ital B}{bold (}{ital x},{ital y},{ital H}({ital t}){bold )},{ital M}{bold (}{ital H}({ital t}){bold )}, and {ital J}{sub {ital c}}{bold (}{ital H}({ital t}){bold )} in hard superconductors for a variety of twin-boundary pinning potential parameters, and for a range of values of the density and strength of the pinning sites. We numerically solve the overdamped equations of motion of up to 10{sup 4} flux-gradient-driven vortices which can be temporarily trapped at {approximately}10{sup 6} pinning centers. These simulations relate macroscopic measurements [e.g., {ital M}({ital H}), {open_quote}{open_quote}flame{close_quote}{close_quote} shaped {ital B}({ital x},{ital y}) profiles] with the underlying microscopic pinning landscape and the plastic dynamics of individual vortices. {copyright} {ital 1996 The American Physical Society.}