Response characterization for an EJ315 deuterium-based liquid scintillation detector

Liquid scintillation detectors have shown promise as neutron detectors for characterizing special nuclear materials in various arms-control applications. Deuterated liquids, such as EJ315, are attractive for spectroscopy applications because the backward-peaked n-d scattering results in enhanced coupling between incident neutron energy and resulting pulse height. In the context of discrete neutron-energy spectra, this produces peaks in detector pulse-height spectra which correspond to the neutron energy groups present. With continuous spectra, increased coupling may yield better spectrum unfolding. In this work, we present a neutron response matrix for a three-by-two-inch cylindrical EJ315 detector, and compare to the hydrogen-based liquid EJ309 in the same active geometry. A 'white' neutron source, obtained with the bombardment of ¹¹B with 5.5-MeV deuterons at the tandem Van de Graaff accelerator at University of Notre Dame, was used for the measurement. Detected neutrons were sorted by time of flight and pulse height into 100-keV energy bins and 50-keVee light-output bins, over the energy-range from 0.5 to 15 MeV. The resulting response matrix represents a full characterization of pulse-height response to neutrons over that energy range.