α ionizing particle radiation detection and damage compensation methods for CMOS active pixel sensors

摘要: In this study, the mechanism and characteristics of the response α particles and the damage caused by them in CMOS active pixel (APS) sensors were investigated. A detection and compensation algorithm for dead pixels caused by α particle ionizing radiation was proposed, and the effects of dead-pixel compensation algorithms were compared and analyzed under different parameter conditions. The experimental results show that α particle response signal has highest accuracy at 9 dB gain, with an obvious "target-ring" distribution. With increasing cumulative dose, the CMOS APS pedestal tends to saturation while dead pixels continue increasing. Though some pixel damage recovers through natural annealing, the dead-to-noise ratio increases with irradiation time, reaching 32.54% after 72 h. A hierarchical clustering dead-pixel detection method is proposed, categorizing pixels into two types: those within and outside the response event. A classification compensation strategy combining mean and majority filtering is proposed. This compensation algorithm can address dead-pixel interference without affecting α particle radiation response data. When iterated multiple times and with integration
time exceeding 6.31 ms, the number of dead pixels can be effectively reduced.