A theoretical comparison of silicon and diamond in microdosimetry

Abstract

Silicon and diamond are regarded as promising solid-state detectors for microdosimetry and have attracted considerable attention in recent years. However, their performance is slightly different due to the difference in physical qualities. In this work, we intend to compare their performance in microdosimetry theoretically from the aspect of tissue equivalence and electronic properties. The tissue equivalence study has shown that diamond exhibits better tissue equivalence than silicon due to the approximation of mean ionization/excitation potential to tissue. And the tissue equivalence of silicon is acceptable when the incident energy is low. In electronic properties comparison, the results indicate that the collection time in the diamond is shorter than that in silicon when aligned in the same configuration, and the current signal induced in CVD diamond is higher than in silicon at low electric fields. The current in natural diamond is greater than silicon at the low electric field only when the energy deposited in silicon and diamond is different. Since the microdosimeter is usually performed at low electric fields in microdosimetry to ensure low electronic noise, the electronic properties of high-quality CVD diamond are superior to silicon for microdosimetry applications. It seems that diamond, especially high-quality CVD diamond, exhibits better tissue equivalence and electronic properties than silicon in microdosimetry.