Recoil studies of the interaction of 48Ca with 18–36 MeV 4He ions and 5–43 MeV 3He ions

Abstract

Thin-target thick-catcher recoil experiments are described for the (α, αn), ( 3He, α) and ( 3He, p2n) reactions on neutron-excess 48Ca with 18–36 MeV 4He ions and 5–43 3He ions. Product distributions between the target and catcher foils are compared with Monte Carlo calculations assuming compound nucleus and direct interaction mechanisms. Using these comparisons the (α, αn) and ( 3He, α) excitation functions are broken down into their direct interaction and compound nucleus components. The direct interaction contribution to the (α, αn) reaction at 36 MeV is in the range of 20 % to 40 %. It is found that the thin-target experiments probably afford better differentiation between direct interaction and compound nucleus mechanisms than the comparable thick-target experiments.