$\gamma $ -Ray Detection Using Commercial Off-the-Shelf CMOS and CCD Image Sensors

Abstract

In this paper, we present the results of research on the response of four types of commercial off-the-shelf (COTS), CMOS, and charge-coupled device (CCD) image sensors to $\gamma $ photons. The aim of this paper was to study the potential use of CCD and CMOS COTS image sensors as $\gamma $ -ray detectors. A 60Co $\gamma $ source was used to study the response behavior of the sensors to the irradiant photons. The results show that the CMOS image sensors have much less background noise before irradiation and have better radiation resistance below 51.24 Gy. The background noise of CCD sensors obviously increases with a larger total ionizing dose. The linearity of the dose-rate response of CCD COTS sensors is better than that of CMOS COTS sensors. Both mean pixel value and cumulative pixel value may be used to obtain the photon dose rate. The sensor technology structure difference leads to the different shapes of events. The Compton scattering of 60Co $\gamma $ photons in silicon caused the recorded patterns to show not only dots but also small streaks or traces. The peak value provides the photon energy, while the peak shape and radius can be used to classify the particle. CMOS COTS sensors are suitable for the particle classification, while CCD COTS sensors are better for energy resolution.