Optical model calculations at Rensselaer Polytechnic Institute

Experimental evidence of deep minima in the p-wave neutron strength function about mass numbers 55 and 160 has been studied via optical model calculation. By employing a spherical optical model with an angular momentum dependent (l) imaginary potential strength (Wsup((l))), a global optical model parameter set has been determined which accurately predicts the s and p-wave neutron strength functions and potential scattering radius over mass numbers 40-240. Extension of the angular momentum dependent optical potential to coupled-channel calculations treating 0+-2+ collective state coupling, improved the agreement between prediction and experimental data. The values Wsup((0))=12MeV and Wsup((1))=1.5MeV employed in the calculations indicate that p-wave neutrons effectively interact less weakly than s-wave neutrons with the target nucleus. (auth.)