The continua excited by inelastic scattering of 26 MeV/A α- and6Li-particles from28Si have been studied at forward angles by coincident detection of γ-rays in final nuclei after particle decay. While the coincident γ-ray spectra in6Li-induced reactions show only transitions in mass A=24, 27 and 28 nuclei, in the α-induced reactions γ-transitions in mass 20 to 28 nuclei were observed. Inelastic6Li-scattering with energy losses between 30 and 80 MeV predominantly leads to γ-transitions in27Si and27Al. We interpret this as due to a dominant direct one-nucleon removal process producing the characteristic "triangular" shapes of the inclusive inelastic6Li spectra.6Li-induced reactions on27Al show a corresponding behaviour. The typical flat α-spectra result from additional truly inelastic processes which lead to highly excited states in the target nuclei and subsequent evaporation of nucleons and α-particles. This is supported by the measured γ-multiplicities and by means of Hauser-Feshbach calculations which allow to deduce that part of the inelastic α-continuum which decays by particle evaporation.
ASJC Scopus subject areas
- Nuclear and High Energy Physics