Latest advances in large diameter SrI:Eu and CLYC:Ce scintillators for isotope identification

摘要

Scintillator crystal detectors form the basis for many radiation detection devices. Therefore,a search for high light yield single crystal scintillators with improved energy resolution, largevolume, and the potential for low cost, is an ongoing process that has increased in recent years due toa large demand in the area of nuclear isotope identification. Alkaline earth halides, elpasolites andrare earth halides are very interesting because many compositions from these crystal familiesprovide efficient Ce3+/ Eu2+ luminescence, good proportionality and good energy resolution. Theyalso have small band-gap leading to higher light yields. Ce3+and Eu2+ are efficient, and the emissionwavelengths in the 350-500 nm region matches well with PMTs and a new generation of Siphotodiodes.In this presentation, we will the present progress made in the crystal growth of thesecompositions, and scintillator properties of large diameter SrI2:Eu2+ single transparent crystals. Thecrystals were grown successfully using the vertical Bridgeman technique. Crystals with differentdiameters of 1”, 1.3”, and 1.5” will be discussed. SrI2:Eu was discovered a half century ago, andwas recently found to be an outstanding material for gamma ray-spectroscopy with high light yield,very good non-proportionality, and excellent energy resolution.We will also discuss growth and properties of larger Cs2LiYCl6 (CLYC) crystals. Recently,it has been shown that crystals from the elpasolite family, including CLYC, can be successfullyemployed for a dual gamma ray and neutron detection, which is possible with the help of pulse shapediscrimination (PSD). PSD allows for recognition of an incident particle’s nature based on the shapeof the corresponding scintillation pulse. CLYC has the potential to minimize the cost andcomplexity of dual sensing gamma ray and neutron spectrometers. We also address progress ingrowth of CLYC crystals with large diameters (1” and 2”) that are transparent and crack free.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.