Development of FPGA based Processing Electronics for Gamma Ray Spectrometer (GRS) and Comparisons between two Different Methods

Abstract: In the instrumentation field, ? rays make their own value because of its high energy nature. The spectroscopy based on ? rays is used in the space exploration programs, nuclear physics, geophysics, medicine & thermonuclear fusion. This paper describes the development of processing electronics & data acquisition system designed for Gamma Ray Spectrometer (GRS) for the future space mission. The surface composition in terms of concentration of major elements is one of the most fundamental information about any planetary body. Gamma ray spectrometer is the mostly used technique to determine the elemental abundances of the elements of the surface and it�s subsurface. High purity Germanium (HPGe) detector is planned to be used in this Gamma Ray Spectrometer. Processing electronics covers the analysis of the analogue data, coming from pulse shaping amplifier. In this analogue data, output of the pulse shaping amplifier is a Gaussian shape pulse, where peak amplitude gives the information of the incoming energy of ? ray. Processing electronics includes event trigger generator, peak detector, ADC & FPGA based setup to generate histogram of ? ray counts. In data acquisition part NI DAQ card & LabVIEW software are used for plotting of the histogram.

Keywords: Filed Programmable Gate Array (FPGA), Analogue to Digital Converter (ADC), Data Aqauisition software (LabVIEW), Data Aqauisition card (NI DAQ card), Gamma Ray Spectrometer (GRS).