Aspects on the shape dependence with energy of point-like events in high resistivity CCDs

Abstract

Fully depleted thick CCDs have been designed for infrared astronomy, but their low read-out noise of the order of approximately 2 e− and their considerable mass of approximately 5.2gr, allows novel uses for them in low energy threshold particle detection applications, such as the CONNIE and DAMIC experiments. In both experiments, the neutrinos or WIMPS will generate e-h pairs in a volume much less than the pixel size, they will produce events like points in the output image, of less than 10 pixels. Is well understood that one of the factors that define the size of the events is the diffusion process. In this work we will demonstrate with experimental results and through simulation, that there is also a dependence of the size with the amount of charge generated by the event, due to charge repulsion effects.