LiInP2Se6, a new semiconductor detector material for high resolution neutron imaging

High spatial resolution crystal diffractometer are important for Neutron single-crystal diffraction (SCD), which is a powerful tools to study the crystal structure and morphology of complicated organic and inorganic materials, and to address structural problems in diverse research areas including nano-structured materials, chemistry, earth sciences, materials science, engineering, and solid-state physics. All these studies, and more, would benefit by an enhanced spatial and temporal resolution of the neutron imaging system with high efficiency and high gamma rejection ratio (GRR). The goal of the proposed effort is to develop semiconducting material, lithium indium phosphor selenide (LiInP2Se6), based neutron detection arrays. LiInP2Se6, has been recently discovered and exhibits an extremely high neutron detection efficiency, and great charge collection efficiency. Furthermore, the large 4.78 MeV Q-value provides an intrinsic potential for excellent neutron/gamma discrimination. In the proposed effort, we will also seek to investigate the potential of semiconducting Chemical Vapor Transport (CVT) grown and Vertical Bridgman (VB) grown LiInP2Se6 for use in single crystal diffractometers with 300 µm spatial resolution and neutron-gamma discrimination ≥10-6. In Phase I, the primary objective is to improve the LiInP2Se6 crystal growth process (VB and CVT) in a way to be able to experimentally verify the desired gamma-neutron discrimination ratio, and to computationally verify that. This research is being carried out in collaboration with researchers at the, Northwestern University, University of Tennessee, Knoxville, and Oak Ridge National Laboratory. In addition to their use in neutron scattering instruments, a system capable of high efficiency detection of neutrons with high spatial resolution and good GRR will find applications in various other systems in research, homeland security, nuclear physics, medical imaging and material sciences.