Antisymmetrized, microscopic calculation for theCa40(n,n)optical potential

An antisymmetrized second-order microscopic calculation of the imaginary optical potential for ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}\mathrm{}(n,n)\mathrm{}$ is made using random-phase approximation transition densities to the intermediate excited states. An optical Green's function is used for the intermediate projectile propagator. Both inelastic and ($n,p$) charge exchange intermediate states of the nucleus are included and a finite range effective projectile-target nucleon interaction is used. The local approximation to the calculated imaginary optical potential is surface peaked but at a smaller radius than most of the phenomenological potentials, and the depth is somewhat smaller. Collectivity and intermediate charge-exchange states are shown to play an important role.