Intranuclear cascade and Fermi breakup calculations ofH1- andHe4-induced reactions on light target nuclei

Abstract

Mass, energy, and angular distribution data for fragments with $A\ensuremath{\ge}6$ produced in intermediate-energy proton- and alpha-particle-induced reactions on $^{12}\mathrm{C}$ and $^{16}\mathrm{O}$ nuclei are compared with the results of an intranuclear cascade calculation followed by deexcitation of the residual nuclei via a Fermi breakup mechanism. In this latter step all possible particle-stable exit-channel states are included in the phase space available for decay. The shapes of the angular distributions are reproduced successfully by the calculation, even at relatively low bombarding energies (e.g., ${E}_{\ensuremath{\alpha}}=60$ MeV). The energy spectra are also reproduced qualitatively. The isobaric cross sections of fragments heavier than the target nucleus are underpredicted for alpha-particle-induced reactions, whereas the yields of fragments with $A=6\ensuremath{-}8$ are overpredicted. The former discrepancy is attributed to the importance of alpha-particle breakup during the cascade while the latter may serve as a measure of the relative importance of statistical multibody breakup mechanisms.[NUCLEAR REACTIONS Intranuclear cascade, Fermi breakup model, evaporation model; calculated $\ensuremath{\sigma}(E,\ensuremath{\theta},A)$ for $^{12}\mathrm{C}(\ensuremath{\alpha},\mathrm{HI})$, $^{16}\mathrm{O}$(p,HI), $^{12}\mathrm{C}$(p,HI); HI: $A=6\ensuremath{-}19$.]