Angular distribution of fast protons from the pre-equilibrium process of the 165Ho( alpha,p) reaction.

Abstract

The concept of the exciton model for nucleon-induced nuclear reactions has been extended to \ensuremath{\alpha}-induced pre-equilibrium reactions in order to calculate angular distributions and energy spectra of fast ejectile nucleons. The effect of the nucleon motion on the cascade nucleon-nucleon scattering inside the nucleus and the geometrical optical effects at the exit channel are taken into account for the first time in the \ensuremath{\alpha}-induced pre-equilibrium reaction. Angular distributions of protons from the $^{165}\mathrm{Ho}$(\ensuremath{\alpha},p) reaction at ${\mathit{E}}_{\mathrm{\ensuremath{\alpha}}}$=109 MeV were calculated. The observed distributions of the fast protons in the pre-equilibrium region were found to be reproduced well by the calculation.