Investigation of thin YAP and YAG scintillator characteristics for Alpha radiation spectrometry

The characteristic of the thin plate (O38x0.25mm) of scintillation detectors YAP:Ce (YAlO3 doped Ce) and YAG (Y3Al5O12 doped Ce) were tested by using the etalons of alpha, beta and gamma radiation with low energies (241Am, 90Sr, 55Fe...) and a standard 222Rn. Those detectors have been developed in Crytur Ltd. For the measurement was used a specially built test assembly comprising encapsulated scintillation detector with calibrated photomultiplier fixed in a black, variable-volume test chamber. All measurements were conducted under precisely defined geometry. The MC 1256 analyzer was used in 256 channel configuration. The focus was on measurement and assessment of the tested detectors surface characteristics, in relation to the light output, spectral resolution capability and peak-background characteristics [1.2]. The tests included extended time period of monitoring related to impact absorption on the surface of detectors and energy calibration. The end result was the selection of the most suitable surface processing for the thin scintillation detectors. These detectors can be assembled into large area arrays, enabling the increase of the detection efficiency, especially for the Alpha activity measurement in radioactive aerosols. The major advantage of these scintillation detectors is their low production cost compared with semiconductor detectors.