Hydrogen Cluster Multifragmentation and Percolation Models

Using a recently developed multi-coincidence technique, the cluster fragmentation resulting from a collision between a high energy {H}₂₇^ + ion with a He target is investigated on an event by event basis. The data obtained are analysed in terms of fluctuations in the fragment size distribution. A comparison with a 3D lattice bond percolation with the same size (27 constituents) shows the presence of a critical behaviour in these finite systems. The importance of the hydrogen cluster's speficity is studied with a second lattice bond percolation of same size with two kinds of bond.