FPGA-based trapezoidal digital pulse shaping in nuclear spectrometry

Abstract

A digital pulse processing is most widely used in nuclear spectrometry for achieving good energy resolution at high count rates. We developed a digital pulse processing system to implement a peak detection algorithm using digital trapezoidal pulse shaping. The incident radiation signal amplified by the preamplifier is converted into digital data through the prefilter and the analog-to-digital converter; then, this signal is shaped into trapezoidal pulses through the implemented algorithm which consists of rising edge detection, pile-up signal discrimination and offset remove, two stages of convolutions, peak detection and ballistic deficit discrimination. We compared a linearity of the system between simulation and experimental results. The noise was calculated using a commercial test input pulser, and then, the 59.5 keV of gamma-ray spectrum with CdTe Schottky detector was obtained using an Am-241 radioisotope source. This system showed better noise characteristics and gamma-ray spectroscopy characteristics than existing commercial analog systems. © 2023, The Korean Physical Society.