Hot-border effects, ordering, and avalanches in planar arrays of superheated superconducting granules

We present results of simulations of transitions in planar arrays of superheated superconducting granules (PASS) immersed in an external magnetic field parallel to the system. Analysis of the behaviour of the system when the external field is slowly increased from zero shows the existence of an interval of external fields for which no transitions are produced. This gap is found to be a consequence of ordering induced by transitions. However, this ordering is different for diluted and for concentrated systems. Avalanches of different sizes with distributions depending on concentration are observed.