Handheld portable neutron gamma discrimination spectrometer for environmental detection

A compact and integrated neutron-gamma discrimination spectrometer that could be utilized for personal dosimetry and emergency response is urgently required. In this study, based on a CLYC scintillator coupled to silicon photomultiplier(SiPM) arrays, we designed a stand-alone, hand-held neutron-gamma discrimination spectrometer. After the analog-to-digital converter (ADC) digitizes the analog signal from the detector, the data is transmitted to a FPGA processor for online real-time processing, and then transmitted to a microcontroller through the serial peripheral interface(SPI) protocol, and the current detection result is displayed in real-time on the touch screen. By using the pulse signal discrimination(PSD) method, the spectrometer can simultaneously measure the spectrum of neutron and gamma events, with a resolution of 8.8% (at 1274.5 keV) and excellent linearity. The figure of merit (FOM) is 2.32 with optimized PSD parameters. The experimental results show that the spectrometer integrates the upper computer and detector, with real-time performance, portability and excellent neutron-gamma resolution. Online operation is realized through the touch screen, which greatly facilitates the real-time detection of radiation in the field environment.