A High-Performance CLYC(Ce)-PVT Composite for Neutron and Gamma Detection

In this paper, we fabricated and characterized a 50 mm diameter × 30 mm composite detector comprised of 9-mm diameter Cs
₂
⁶
LiYCl
₆
(Ce) [CLYC(Ce)] rods embedded in scintillating polyvinyltoluene (PVT). The CLYC(Ce) rods contributed to 42% of the total weight and 18.5% of the total composite volume. The scintillation performance of the CLYC(Ce)-PVT composite detector matched that of a stand-alone CLYC(Ce) crystal, with an energy resolution of 4.4% and a light yield of 18 100 ph/MeV at 662 keV. Furthermore, the composite showed excellent pulse shape discrimination, with a figure of merit of 3.2. This composite is useful for both spectroscopic and counting applications, the latter being facilitated by the high sensitivity of the scintillating polyvinytoluene. This paper demonstrates that composites offer an affordable route to large detector sizes (e.g., larger than 3-in diameter) and geometries (e.g., panels) beyond those achievable through standard crystal growth techniques.