Development of gamma spectroscopy employing NaI(Tl) detector 3 inch × 3 inch and readout electronic of flash-ADC/FPGA-based technology

Abstract In this article the development of a gamma spectroscopy system is described using a scintillation detector NaI(Tl) of 3 inch × 3 inch. The readout electronic for the spectroscopy is built from the fast analog-digital conversion of Flash Analog-Digital Converter (Flash-ADC) 250 MHz – 8 bits resolution, and the embedded Field-Programmable Gate Array (FPGA) technology. The embedded VHSIC Hardware Description Language (VHDL) code for FPGA is built in such a way that it works as a multi channel analyser (MCA) with 4096 Digital Charge Integration (DCI) channels. A pulse generator with frequency varying from Hz up to 12 kHz is used to evaluate the time response of the system. Two standard radioisotope sources of 133Ba and 152Eu with multi gamma energies ranging from several tens keV to MeV are used to evaluate the linearity and energy resolution of the system.