A 4H silicon carbide based fast-Neutron detection system with a neutron threshold of 0.4 MeV

Special requirements in pulsed fast-neutron detection of prompt fission and fusion devices call for a detection detector or system which could detect fast-neutrons in a severe radiation field, and thus should necessarily have a flat energy response, a high signal-noise-ratio, proper threshold energy, and a good radiation resistance. In this paper, a fast-neutron detection system based on a thin silicon carbide (SiC) detector and a ²³⁷Np fission target was developed and tested on Xi'an Pulsed Reactor, which was with a neutron threshold of 0.4 MeV, a flat energy response to neutrons in the range of 1 MeV to 20 MeV and got good response spectra to fission fragments. The SiC detector used here is a 4H-SiC Schottky diode detector with the dimension of 20 mm × 20 mm × 20 μm, a dark current of lower than 5 nA within 600 V, a best energy resolution to alpha particles of about 1.78% and a high radiation resistance under alpha particle irradiation with a max incident number of 1.03 × 10¹⁰. The detection system shows advantaged prospects in fast-neutron fluence monitoring in nuclear fission and fusion equipments.