A Design Configuration of an FPGA-Based Coincident Spectrometry System

Abstract

In the past, most of popular coincidence spectrometers were normally based on traditional electronics techniques such as time to amplitude conversion or logic selecting coincidence unit. They were complicated and it is not convenient for us to use them. This paper deals with a new design of a contemporary coincidence spectrometer which is based on Field Programmable Gate Arrays (FPGA) devices via Digital Signal Processing (DSP) techniques with Hardware Description Language (VHDL). The outstanding advantage of DSP techniques and FPGA technology is capable of enhancement of the quality of the experimental measurements for nuclear radiation. The designed configuration of the traditional system was tested on the PCI 7811R board of National Instruments while the digital systems were establishing with FPGA devices. The purpose of this work is referring to the principle for construction of an FPGA-based system capable of replacing a conventional system. Therefore, a novel approach for in-house development of digital techniques is presented. The method for designing the system is utilization of slow-fast coincidence configurations with two HPGe detectors obtaining a pair of coincidence events, processing data in DSP algorithms. The significant and noticeable results are the operating frequency of 80 MHz and system timestamp window of approximately 10 ns.

In-house development of an FPGA-based MCA8K for gamma-ray spectrometer

“…These instruments are designed for high precision γ-ray spectroscopy with HPGe detectors and directly compatible with scintillator/PMT combinations: NaI, CsI, BGO, etc. As known, The DGF Pixie-4 is a multichannel data acquisition system for nuclear physics and other applications requiring coincident radiation detection (XIA LLC 2009 ), or the work for development of a fast flash ADC for nuclear spectroscopy system (Hien and Toshihiko 2001 ), or the issue for development of an FPGA based coincident system (Khang et al 2013 ). Owing to a flexible inner structure in defining and changing the functions of electronics circuits by programming, FPGA expresses its capability for applying in gamma ray spectroscopy.…”