Year
2010
Abstract
Neutron spectroscopy has direct application to the detection of special nuclear materials (SNM) for nuclear safeguards and nonproliferation. Standard hydrogen-based liquid scintillators have been investigated for their potential nuclear safeguards and nonproliferation applications. However, deuterated liquid scintillators such as C6D6 (deuterated benzene, EJ315) show promise in providing more detailed energy information about detected neutrons than their hydrogen-based counterparts, such as BC501 and EJ309, at neutron energies greater than 2.5 MeV (1) (2). We will consider application of deuterated scintillators to neutron sources relevant to nuclear safeguards and nonproliferation (for example fission sources such as 252Cf). Detection of SNM in the presence of diverse background radiations also requires reliable pulse-shape-discrimination (PSD), and detection efficiency comparable to hydrogen-based liquid scintillators. Here, we present PSD characteristics and measured intrinsic neutron detection efficiency for a 2×2-inch cylindrical C6D6 (EJ315) scintillator. Detection efficiency is measured as a function of incident neutron energy from 0.5 to 5 MeV using a bench-top time-of-flight technique and a 252Cf source. PSD capabilities are compared with those of the hydrogen-based EJ309. In addition, simulations of efficiency versus energy for geometrically identical C6D6 and C6H6 detectors have been performed using the Monte Carlo code MCNP-PoliMi.