Neutron Total Cross Section Measurements at Intermediate Energy

New measurements of neutron total cross sections have been performed as a function of neutron energy up to 600 MeV using the WNR facility at Los Alamos National Laboratory. Transmission measurements were performed for eighteen target nuclei with 9 < A < 209 including isotopically enriched samples of 40Ca, 90Zr and 208Pb. While the goal of the experiment was to measure total cross sections above 100 MeV in small energy bins and with 1% statistical accuracy, much of the data at lower energy is significantly better than that. Rapid fluctuations In the cross sections of light nuclei below 20 MeV provide information on nuclear level density at high excitation energy. The overall dependence of the cross section on neutron energy can be interpreted in terms of optical models ranging in complexity from simple Ramsauer pictures to Dirac phenomenology. Preliminary results of some of these calculations will be presented.