Natural radiation events in CCD imagers at ground level

In charged coupled devices (CCDs), radiation-induced events generate electron hole pairs in silicon that cause artifacts and contribute to degrade image quality. In this work, the impact of natural radiation at ground level has been characterized at sea level, in altitude and underground for a commercial full-frame CCD device. Results have been carefully analyzed in terms of event shape, size and hourly rates. The respective contributions of atmospheric radiation and telluric contamination from ultra-traces of alpha-particle emitters have been successfully separated and quantified. Experimental results have been compared with simulation results obtained from a dedicated radiation transport and interaction code.