The application of digital signal processing method to develop an algorithm for neutron-gamma pulse shape discriminator

Abstract

The measurement of neutron energy has been required in many fields of sciences such as nuclear reactor equipment, particle physics, material research and so on. However, the contribution of gamma background into the spectrum causes neutron spectrum to be less accurate. Therefore, the discrimination of gamma-ray events in neutron spectrum is essential. As the difference in the output signal of detector when interacting between neutron and gamma rays that allows establish an algorithm for separating neutron-gamma. In this article, algorithm for digital implementation of the charge-comparison method for n/γ discrimination based on digital signal processing technique is described. The development of an FPGA based digital signal processing system has been undertaken for this application. In particular, the development kit named Spartan 6 FPGA was used as a hardware for the development of a pulse shape discriminator, and is equipped with ADC 6645 14 bit-100 MSPS. The entire system has been tested with He-3 counter, using thermal neutron source from Da Lat reactor.