FPGA based Single Channel Analyzer (SCA) used for nuclear radiation counting system

Abstract

Hardware configurable Single Channel Analyzer (SCA) is designed and developed to improve the performance and flexibility of the system compared with traditional approaches. In this work, a new technique has been introduced for changing the window between the Upper Level Detection (ULD) and the lower Level Detection (LLD) for SCA by a simple change in software, without any hardware modification. To check this technique, electric pulse generated from the detector conditioned by a preamplifier is fed to ADC through a processing circuit. When the ADC output value is higher than the LLD and lower than the ULD, then counter will count those values over a period of one minute and store the counting value in a register. Finally the stored counting values are given to LCD through other necessary circuits. In addition, maximum peak value, counts per minute and total counting value are also displayed on LCD. Associate firmware has been developed by Xilinx ISE Design suite 9.2 using VHDL code and tested on Xilinx Spartan 3E Starter board. This developed system may be effectively used for radiation monitoring of human body as well as environment.