Taking the CCDs to the ultimate performance for low threshold experiments

SOFO HARO, M.; FERNANDEZ MORONI G.; TIFFENBERG, J.; CANCELO, G.; ESTRADA, J.; BERTOU, X.; PAOLINI, E.E.

Chicago

Conferencia; 38th International Conference on High Energy Physics (ICHEP2016); 2016

Scientific grade CCDs show attractive capabilities for the detection of particles with small energydeposition in matter. Their very low threshold of approximately 40 eV and their good spatialreconstruction of the event are key properties for currently running experiments: CONNIE andDAMIC. Both experiments can benefit from any increase of the detection efficiency of nuclearrecoils at low energy. In this work we present two different approaches to increase this efficiencyby increasing the SNR of events. The first one is based on the reduction of the readout noiseof the device, which is the main contribution of uncertainty to the signal measurement. Newstudies on the electronic noise from the integrated output amplifier and the readout electronicswill be presented together with result of a new configuration showing a lower limit on the readoutnoise which can be implemented on the current setup of the CCD based experiments. A secondapproach to increase the SNR of events at low energy that will be presented is the studies of thespatial conformation of nuclear recoil events at different depth in the active volume by studies ofnew effects that differ from expected models based on not interacting diffusion model of electronsin the semiconductor.