Effect of Very High-Fluence Proton Radiation on 6H-SiC Photoconductive Proton Detectors

Abstract

In this work, the effect of very high-fluence 100 MeV proton radiation on the performance of 6H-SiC photoconductive proton detectors is studied. The irradiation fluence is up to <inline-formula> <tex-math notation= LaTeX >${1.6}\\times {10}^{{{17}}}{\\mathrm {cm}}^{{\\text {-2}}}$ </tex-math></inline-formula> and the degradation process of the SiC detector is continuously monitored for the first time. Before proton irradiation, the detector shows a low dark current of ~0.8nA/cm² at 1000 V bias. As the irradiation fluence increases, the dark current continuously drops, which should be caused by irradiation damage induced carrier compensation defects. Meanwhile, the output current of the SiC detector shows an exponential decay behavior and tends to saturate at irradiation fluence up to <inline-formula> <tex-math notation= LaTeX >${5}\\times {10}^{{{16}}}{\\mathrm {cm}}^{{\\text {-2}}}$ </tex-math></inline-formula>. At the end of the very high fluence irradiation test, the detector still exhibits ~20% of its original output current value, suggesting the excellent radiation hardness of SiC for proton detection.