Development and verification of a simulation toolkit for Self-Powered Neutron Detector

A response simulation toolkit 'SPNDSignal' based on Geant4 was developed and verified. SPNDSignal adopts Monte-Carlo method to simulate the coupled neutron-gamma-electron transportation in SPND, and the important physical parameters such as neutron sensitivity and current components can be obtained. Compared with present Monte-Carlo simulation tools, SPNDSignal has advantages: (1) current components induced by neutron and external gamma in reactor can be calculated only through one-step simulation; (2) space charge effect can be considered by simulating electron transportation in real electric field; (3) information of particles obtained by fuel assembly calculation, such as vertex position, kinetic energy, etc., can be directly used as particle source, thus particle information loss and coupling work between different programs can be greatly reduced. The verification work is performed for rhodium, vanadium, silver and hafnium detectors. The simulated neutron sensitivities are in good agreement with experimental results. Moreover, background current of Cobalt SPND was also studied. (C) 2020 Elsevier Ltd. All rights reserved.