Simulations of the measurement results of differential cross sections of n-p and n-d elastic scattering at CSNS Back-n WNS

Differential cross-section data for the n-p and n-d elastic scattering (H-1(n, el), H-2(n, el)) are collected and analyzed from EXFOR library. For E-n > 20 MeV, the experimental results for both reactions are scarce with large uncertainties and discrepancies in general. For E-n <= 20 MeV, the experimental results lack systematicness, most of which were measured around E-n = 14 MeV even though the differential cross sections of n-p scattering in 1 keV <= E-n <= 20 MeV region are recommended as standard. Taking these facts into account, more accurate and systematic measurements are planned. The experiments will be conducted using Delta E-E detectors of the Light-charged Particle Detector Array (LPDA) system at China Spallation Neutron Source (CSNS) Back-n White Neutron Source (WNS), and simulations are carried out. Using polyethylene and deuterated polyethylene as samples, both n-p and n-d scattering reactions are simulated along with the neutron-induced C-12 background reactions, and the 2-D spectra and the counting rates of the Delta E-E detectors are obtained. According to the simulations, the applicable neutron energy range and positions of the detectors are recommended, and the beam time for the event and background measurements is suggested.