Systematics on cluster production and kinetic energy spectra in spallation reactions

The cluster yields are contributed from the preequilibrium emission in the cascade collisions and from the statistical decay via the hot fragments, in which the surface coalescence and GEMINI statistical decay are used for the cluster production.

The spallation reactions of proton, deuteron, triton, \(^3\mathrm{He}\) and \(\alpha\) on \(^{208}\mathrm{Pb}\), \(^{209}\mathrm{Bi}\) and \(^{232}\mathrm{Th}\) are systematically investigated. It is demonstrated that the energetic clusters are mainly contributed from the preequilibrium emission, in particular at the kinetic energies above 30 MeV. The more bound nucleus is available for the production in the spallation reactions, i.e., the larger yields for \(\alpha\) in comparison with \(^3\mathrm{He}\).