FRAGMENTATION OF PERCOLATION CLUSTER PERIMETERS

We introduce a model for the fragmentation of porous random solids und er the action of an external agent. In our model, the solid is represe nted by a bond percolation cluster on the square lattice and bonds are removed only at the external perimeter (or 'hull') of the cluster. Th is model is shown to be related to the self-avoiding walk on the Manha ttan lattice and to the disconnection events at a diffusion front. The se correspondences are used to predict the leading and the first corre ction-to-scaling exponents for several quantities defined for hull fra gmentation. Our numerical results support these predictions. In additi on, the algorithm used to construct the perimeters reveals itself to b e a very efficient tool for detecting subtle correlations in the pseud orandom number generator used. We present a quantitative test of two g enerators which supports recent results reported in more systematic st udies.