Real-time pulse-shape discrimination and beta-gamma coincidence detection in field-programmable gate array

A real-time FPGA-based algorithm has been developed and tested to discriminate pulse-shapes, identify beta-gamma coincidence events and collect energy spectra from xenon radioisotopes using a phoswich detector. The detector consists of a thin plastic scintillator (BC-400) to detect beta and conversion electrons, a CsI(Tl) crystal for measuring X-rays and gamma-rays, and a BGO crystal, which surrounds the CsI(Tl) layer, to identify scattered photons and ultimately to reduce Compton continuum in the gamma energy spectrum. In this paper, we report on the detail of the FPGA hardware design, the pulse-shape discrimination method, and the system's operational modes. In addition, our initial real-time radioxenon measurement results with the phoswich detector are presented.