Elastic and inelastic neutron scattering at 65 MeV

Elastic scattering cross sections for 65 MeV neutrons incident have been measured for natural targets of C, Si, Ca, Fe, Sn, and Pb at lab angles from 6 to 48 degrees. Inelastic (n,n'x) continuum measurements for natural Fe, Sn, and Pb have also been carried out. These are some of the first measurements using our new proton-recoil detection system which allows a large angular and energy range of scattered neutrons to be measured at one time. Wire chambers and large area E and ΔE detectors are used in conjunction with a CH2 converter. Time-of-flight is used only to establish the energy of the incident neutron in a collimated beam produced by 7Li (p,n). The elastic data are compared to the predictions of several optical model potentials, and to a microscopic potential generated from effective interactions and nuclear densities. The inelastic (n,n'x) data are compared to similar-energy (p,p'x) data over the giant resonance excitation energy range of the continuum. A macroscopic model analysis is used to extract the ratio of the neutron to proton matrix elements, Mn/Mp. The ratio is found to be consistent with the macroscopic (hydrodynamic) model (Mn/Mp ≅ N/Z), and inconsistent with pion inelastic scattering results, which are interpreted in terms of a larger ratio