A multi-physics simulation study of 4H-SiC detector for proton-boron fusion reaction diagnostics

Proton-boron (p-11B) fusion demands robust diagnostic tools capable of operating in high-temperature, high-radiation environments with significant X-ray backgrounds. Silicon Carbide (SiC) detectors offer inherent advantages including high-temperature tolerance, radiation hardness, and insensitivity to visible light. This paper presents a multi-physics simulation study of a 4H-SiC detector for alpha particle detection in p-11B fusion environments using the RASER(RAdiation SEmi-conductoR) simulation platform, which integrates DevSim, Geant4, and NGspice for end-to-end device-to-electronics simulation. The detector features a junction termination extension (JTE) structure to ensure reliable high-voltage operation. Temperature-dependent simulations are performed at 300 K, 400 K, and 500 K. Results show that the optimized detector achieves full depletion at 460 V. The leakage currents is 2.8 nA at 300 K and remains stable at 2.8 nA at 500 K. The detector exhibits linear response to alpha particles (3–4 MeV) with signal-to-noise ratio exceeding 123, and pulse height spectra reveal clear amplitude and charge separation between alpha and X-ray signals enabling simple threshold-based background rejection. Fast carrier transport properties of SiC enable high-count-rate capability. Based on the optimized design, detector fabrication has been initiated. This study validates the feasibility of SiC detectors for p-11B fusion diagnostics.