Use of a standard CMOS imager as position detector for charged particles

Recent developments in the domain of standard CMOS imagers for visible light, mainly in the reduction of the pixel size due to the scaling of the technological node, have led us to investigate the suitability of some of these devices as ionizing radiation detectors. A standard VGA imager with 5.6×5.6 micrometer pixel size has been choosen. It has been characterized using laboratory sources and charged particles beams. The main results obtained are: small average pixel multiplicity (4–5) for the detection of charged particles, S/N value ∼ 30, intrinsic spatial resolution at 620 nanometers, efficiency close to 100% with small fake hit rate.