Total cross sections for 4,6He + 28Si reactions measured at 10–28 MeV/A

New results on the energy dependence of the total cross section (σR) for 6He scattering on 28Si in the incident energy range 10–28 MeV/A are obtained. The α-particle-production cross sections for the 28Si(6He, 4He)X channel are measured as well. The secondary beam of 6He with an intensity of up to 5×104 particle/s was generated by bombarding a thick beryllium target with ∼32-MeV/A7Li ions. In the energy region below 17 MeV/A, σR increases sharply. The experimental dependences of the total cross sections are compared with the results of σR calculations using the double-folding potential within the optical model. The energy dependence of σR for 6He differs from that for the neighboring nuclei, which can be associated with the structural features of the former nucleus. The energy spectra of α particles produced in the 6He interactions with silicon indicate two mechanisms of their production: transfer reaction and 6He breakup in the field of the 28Si nucleus.