Simultaneous recording of high-energy photon spectrum using phoswich detector

Abstract

Phoswich detector with its pulse shape discrimination (PSD) electronics is being used for estimating actinides in lung as part of in vivo monitoring. In this application, only the signals from thin NaI (low energy measurement) are effectively utilized. The high-energy gamma interactions in thick CsI portion of phoswich are merely used for background reduction in the low-energy regions. The present PSD electronics was suitably modified; both lower and higher energy photon spectra from a single phoswich detector are recorded simultaneously. This feature helps in identifying any fission product gamma emitters and also detects the increase in background during lung counting measurements. This paper outlines the modifications incorporated in the PSD electronics and the suitability of phoswich detector as a gamma ray spectrometer. The typical spectrometric characteristics of the detector such as energy linearity, full width at half-maximum, point source efficiency, and so on, estimated through experiments, and some of the salient results are highlighted.