The ways of characteristics improvement for alpha–beta detectors on ZnSe based composite scintillators

The design and technological scheme of alpha particle detectors based on crystal granules of ZnSe–Al were developed. We have found that the ZnSe–Al semiconductor scintillator has a number of advantages compared to the ZnS–Ag namely the terms of sensitivity and the ability to obtain scintillation powder of the desired dispersion. The results of tests of sensitivity, homogeneity and ability to registration simultaneously both alpha and beta particles are presented. The measured sensitivity of detectors towards alpha particles (²³⁹Pu source) was more than 0.3 pulse per sec/Bq (pps/Bq) and towards beta particles (⁹⁰Sr-⁹⁰Y source) was more than 0.25 pps/Bq. The light output inhomogeneity of scintillators within the area did not exceed 2%. This makes it possible to produce the large area detectors. An algorithm for separating the scintillation signal from alpha and beta particles during their simultaneous registration is proposed. Potentially, statistical algorithms will allow 100% separation of alpha and beta particle pulses.