Light-charged-particle evaporation from hot ³¹P nucleus at E^∗~60 MeV

Abstract

The inclusive energy spectra of light charged particles, such as, a, p, d and t, evaporated from the hot ³¹P nucleus at an excitation energy E ~ 60 MeV, have been measured at various angles. The compound nucleus ³¹P has been populated using two different entrance channel configurations; i.e., ⁷Li (47 MeV) + ²⁴Mg and ¹⁹F (96 MeV) + ¹²C reactions, leading to the same excitation energy of the compound system. It has been observed that the spectra obtained in the ⁷Li (47 MeV) + ²⁴Mg reaction follow the standard statistical-model prediction with a spherical configuration of the compound nucleus. But, the spectra obtained in the ¹⁹F (96 MeV) + ¹²C reaction deviate from similar predictions of the statistical model both on higher- as well as on lower-energy sides. Considerable deformation was required to be incorporated in the calculation in order to reproduce the measured-energy spectra in this case. Dynamical trajectory model calculations were not found to play any significant role in explaining the differences in behaviour between the two cases under study. The observed discrepancy has been attributed to the difference in the angular-momentum distributions of the compound nuclei formed in the two reactions.