Development of an associated particle imaging system with pixel SiC detectors

The elemental analysis method, with fast neutron associated particle imaging, holds immense potential in identifying concealed explosives, nuclear materials, and container security inspection, owing to its superior sensitivity and three-dimensional analysis capability compared to traditional neutron activation analysis technology. However, the temperature and irradiation fragility of the traditional associated particle detector curtails its usage in harsh environments such as space missions. The adoption of wide-bandgap semiconductor detectors, such as SiC, is expected to address this constraint. In this work, an associated particle imaging system based on a 4 × 4 SiC pixel detector was designed, built, and tested. The SiC detector exhibited consistent energy resolution and time performance between 25–150 °C. The built API system achieved an intrinsic time resolution of 1.8 ns and spatial resolution of at least 10 cm in the neutron flight direction. By utilizing the coincidence time spectrum and pixel SiC detector, the built system can provide the element content distribution in three-dimensional space. The results demonstrate the feasibility of employing SiC detectors in associated particle imaging systems and pave the way for developing a new type of sealed neutron tube with a prolonged lifetime and high environmental adaptability.