Excitation Function of the ReactionBe9(Li7,Li8)Be8

The cross section and thick-target yield as a function of energy are derived for the reaction ${\mathrm{Be}}^9$ (${\mathrm{Li}}^7$,${\mathrm{Li}}^8$) ${\mathrm{Be}}^8$ over the laboratory energy range 1.1 to 4.0 Mev. A model is assumed in which the ${\mathrm{Li}}^7$ picks up the final, loosely-bound neutron of ${\mathrm{Be}}^9$ only at radial positions considerably outside the nuclear surface, direct reactions being prevented by the Coulomb repulsion.