Quasi-Free α-α Scattering in Be 9 and C 12 at 37 MeV

Energy and angular correlations between two alpha particles from the Be 9 (α, 2α)He 5 and C 12 (α, 2α)Be 8 reactions were investigated. The incident alpha particle energies were 32.3 MeV and 37.4 MeV for Be 9 and 37.4 MeV for C 12 . It is concluded that the quasi-free scattering of incident alpha particles from alpha clusters in Be 9 is the main process of the (α, 2α) reaction on Be 9 . It remains some ambiguity for the mechanism of the (α, 2α) reaction on C 12 to be explained as a simple quasi-free scattering process.