Obtaining High-Dose-Rate $\gamma$ -Ray Detection With Commercial Off-the-Shelf CMOS Pixel Sensor Module

This paper presents the response of a commercial off-the-shelf (COTS) complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) module to γ-rays delivered from Cobalt-60 at a high-dose rate and evaluates its performance as a potential high-dose-rate and wide range γ-ray detection device. The experimental results show that the rate of noise generation is not linear with respect to the total ionizing dose, and the radiation damage sustained by the sensor modules exhibits a total ionizing dose threshold. A conservative value of this threshold for the test sensor is 38 Gy. In addition, the average pixel gray level value and the proportion of pixels responding to radiation increase with increasing dose rate, and linear responses are obtained for both in the dose rate range of 5.24-69.24 Gy/h. The upper limit of the linear radiation response range depends on the capability of the COTS sensor module, while the lower limit depends on the number of radiation response events in a frame; the upper limit of the linear response range can be increased by reducing the integration time. This paper provides valuable suggestions for adopting CMOS-APSs for high-dose-rate and wide range radiation detection, and it is an important complement to our previous studies focused on the linear response of the CMOS-APS under low-dose-rate irradiation.