Measurements of fast neutron scattering on carbon via a diamond detector at LANSCE*

Plastic scintillators are widely used for neutron detection. For example, the Modular Neutron Array (MoNA) is used at the Facility for Rare Isotope Beams (FRIB) to detect fast neutrons in the study of neutron-unbound systems. In radioactive beam experiments that produce fast neutrons, the possibility of dark scattering, where the neutron scatters on a carbon nucleus in the plastic and doesn’t produce sufficient light to be detected, is high. If that scattered neutron hits another bar and then produces light, the position vector of the detected neutron will be constructed incorrectly. An experiment at the Los Alamos Neutron Science Center (LANSCE) was performed to investigate interactions between fast neutrons and carbon nuclei to better understand the scattering patterns of these interactions. A subset of MoNA plastic scintillators were installed downstream of two spectroscopic diamond detectors. Coincident measurements were made between a diamond detector and the MoNA bars. Scattering observables from the neutrons and light charged particles were reconstructed for a range of incoming neutron energies from 20 MeV to 400 MeV. The properties of the diamond detector also allow specific reaction channels to be investigated. Preliminary results will be presented.