Scintillation and dosimeter properties of LiAlSi2O6 and LiAlSi4O10 crystals

Abstract

Optical, scintillation, optically stimulated luminescence, and thermally stimulated luminescence properties of nondoped LiAlSi2O6 and LiAlSi4O10 mineral crystals were investigated. The photoluminescence emission wavelengths of LiAlSi2O6 and LiAlSi4O10 were 300-500 and 350-600 nm, respectively, and the scintillation emission wavelengths were similar. Under vacuum ultraviolet photon excitation at a synchrotron facility (UVSOR), excitation bands of LiAlSi2O6 and LiAlSi4O10 appeared at around 150 and 180 nm, respectively. The decay lifetime of LiAlSi2O6 was on the nanosecond order while that of LiAlSi4O10 was on the millisecond order for both photoluminescence and scintillation. Both samples showed thermally stimulated luminescence, and LiAlSi4O10 had a higher sensitivity. When we investigated optically stimulated luminescence, LiAlSi4O10 exhibited a detectable signal, while we could not observe a signal in LiAlSi2O6.