Evaluation of a lithium-glass based composite neutron detector for $^{3}$He replacement

In light of the reduction of the world's supply of helium-3 and the increasing demand for neutron detection in the fields of physics research, national security, and nuclear energy, the need for a suitable alternative to $^{3}$He-based detector technology is of paramount importance. It is critical that a potential replacement boast both high neutron detection efficiency and insensitivity to, or the ability to discriminate against, gamma-ray backgrounds. Recent efforts investigating the use of composite detectors, specifically highly neutron-sensitive scintillators embedded in scintillating acrylic, have shown promise but need further improvements to be competitive with moderated helium-3 tubes. Endeavoring to increase the neutron detection efficiency over composite detectors of earlier efforts, we have fabricated a 5'' x 5'' cylindrical detector of polyvinyltoluene embedded with 1.5-mm lithium-glass cubes composing 10{\%} of the total mass. The results of both simulations and experiments comparing our Li-glass based composite detector to other composite technologies and to $^{3}$He are presented. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-XXXXXX.