Applicability of optical model potentials for intermediate-energy nuclear data evaluations in the 1p-shell mass region

Applicability of two kinds of optical model potentials to evaluation of neutron nuclear data for the 1p-shell mass region (6Li to 16O) has been studied in the intermediate energy region (20 to 100 MeV). A global optical potential proposed by Walter and Guss, and a microscopic one by Jeukenne-Lejeune-Mahaux (JLM) have been chosen as representatives of the phenomenological and microscopic approaches, respectively. The total and reaction cross sections, and elastic and inelastic scattering angular distributions calculated by using these potentials have been compared with experimental data. It was found that both the potentials give good explanation of the experimental values in spite of the fact that these potentials were not adjusted in this mass region. The present results have indicated that the JLM potential is suitable to the intermediate-energy nuclear data evaluation for the 1p-shell mass region. A qualitative interpretation of the sensitivity of the total cross section to the parameters in the JLM approach has been carried out; it was found that the oscillatory and phase-correlated pattern of the sensitivity coefficients to the real and imaginary potential strengths obeys a simple sine- and cosine-rule with the amplitude decreasing as E-1/2 as derived by a semi-classical model. (author)