Antisymmetrized, microscopic calculation for the 40Ca(n,n) optical potential

An antisymmetrized second-order microscopic calculation of the imaginary optical potential for 40Ca(n,n) 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