Draft 0.2 Comparison of Lithium Gadolinium Borate Crystal Shards in1

We present a method for detecting neutrons using scintillating lithium gadolinium borate crystal8 shards in a plastic matrix while maintaining high gamma rejection. We have procured two cylin-9 drical detectors, 5”×5”, containing 1 % crystal by mass. Crystal shards have a typical dimension10 of 1 mm. One detector was made with scintillating plastic, and one with nonscintillating plastic.11 Pulse shape analysis was used to reject gamma ray backgrounds. The scintillating detector was12 measured to have an intrinsic fast fission neutron efficiency of 0.4 % and a gamma sensitivity of less13 than 2.3 × 10−9, while the nonscintillating detector had a neutron efficiency of 0.7 % and gamma14 sensitivity of (4.75±3.94)×10−9. We determine that increasing the neutron detection efficiency by15 a factor of 2 will make the detector competitive with moderated 3He tubes, and we discuss several16 simple and straightforward methods for obtaining or surpassing such an improvement. We end with17 a discussion of possible applications, both for the scintillating-plastic and nonscintillating-plastic18 detectors.19 a Corresponding author