Simulation of the charge collection characteristics of the 4H-SiC PIN fast neutron detector with TCAD

Abstract

For evaluating the charge collection characteristics of 4H-SiC PiN detector in fast neutron detection based on recoil proton method, the energy spectrum the scattering angle θ of the recoil protons produced by ²⁴¹Am-Be neutron irradiation on fast neutron converter (polyethylene) were simulated with Geant4 toolkit. The energy range of the recoil protons simulated is covered 0~10MeV with the scattering angle varied within 0~60°. The simulation results proved that the higher proton energy, the smaller the corresponding scattering angles based on the physical mechanism of neutron elastic scattering interaction with converter material. The charge collection characteristics of 4H-SiC detector were numerically simulated with TCAD based on Geant4 simulation results by sampling the recoil proton energy and scattering angle (E, θ) as the input parameters. The detector charge collection characteristics changed with the recoil proton energy E (or the corresponding LET value), the scattering angle θ and the proton incident positions on the detector were compared and analyzed.