Deuterated stilbene (stilbene-d12): An improved detector for fast neutrons

Abstract

We have developed and evaluated two prototype fast neutron deuterated-stilbene scintillators. The largest scintillator is hexagonal in shape with volume 32 cm3, comprised of deuterated crystalline trans-stilbene (stilbene-d12). These samples were grown using a solution-based crystal growing method developed at Lawrence Livermore Laboratory to grow conventional 1H-based stilbene scintillator crystals. The stilbene-d12 prototype detectors show excellent neutron/gamma discrimination, noticeably better than 1H-stilbene, and appear to have less asymmetry in the response to neutrons incident from different directions. Like other deuterated scintillators, the stilbene-d12 detectors in many applications can provide incident neutron energy spectra, without time of flight, by suitably unfolding the neutron light-output spectra.