Performance characterization of scintillators using a method of enhanced layered wavelength shifting coatings (Conference Presentation)

Abstract

Many application areas, including space-based and compact fieldable devices, use scintillator systems that require high quantum efficiency and small size, weight, and power consumption (SWAP). Advancements in semiconductor readout devices, such as silicon Avalanche Photodiodes (APD) provide a low SWAP alternative to conventional photomultiplier tubes (PMTs) and provide larger quantum efficiency over a broader spectral range. Direct replacement of PMTs by APDs can degrade system performance because the optimal detection sensitivity of APDs (~700 nm) is poorly matched to the emission of most scintillators (~300-500 nm). Wavelength-shifters can mitigate this performance degradation, however there are many parameters that must be optimized. We will describe our generalized method of applying layers of wavelength shifting dyes to scintillators coupled with state-of-the-art APD readout devices. We will present recent results using single dye layers (YSO:Ce), multiple dye layers (LiCaF:Ce), neutron sensitive scintillators (LiCaF:Ce), and hygroscopic scintillators (CsI:Na) to provide a robust proof of concept of this method for other high performance scintillators (e.g. LaBr3 and CLYC). Improvements in the measured light collection efficiency and energy resolution are supported by photoluminescence, radioluminescence, and absolute quantum efficiency measurements.