A new model for production of fast light clusters in spallation reactions

A model is proposed to describe emission of light charged clusters during the cascade stage in nucleon-induced spallation reactions. It consists in implementing a surface percolation procedure into the Liege intranuclear cascade (INCL4) model: when a nucleon is ready to leave the nuclear surface, it is allowed to drag along a cluster of nucleons, under some conditions of closeness in phase space. This possibility relies on the instantaneous dynamical phase space occupancy in the nuclear surface. The following clusters are considered: d, t, (3) He, (4) He. Good agreement is obtained with experimental data relative to heavy and medium-heavy targets at two different energies. It is shown that the implementation of light cluster emission in the cascade stage also improves our previous results for residue mass spectra. (C) 2004 Elsevier B.V. All rights reserved.