Neutron total cross section in Ca and Fe at 35.3, 40.3, and 50.4 MeV

Abstract
The neutron total cross sections of natural calcium and iron have been measured at 35.3, 40.3, and 50.4 MeV with an overall precision better than 3%. The data suggest a smooth energy dependence. Comparisons with optical model predictions are made. Separation of total cross section into elastic and nonelastic components provides a clue for improvement of optical model parametrizations. A measurement of the total cross section on carbon at 50.4 MeV is also reported.