Achieving sub-electron readout noise in Skipper CCDs

The readout noise for Charge-Coupled Devices (CCDs) has been the main limitation when using these detectors for measuring small amplitude signals. A readout system for a very low noise scientific CCD is presented in this paper. The Skipper CCD architecture, and its advantages for low noise applications are discussed. A technique for obtaining sub-electron readout noise levels is presented, and its noise and signal characteristics are derived. Some experimental results that confirm the low-noise performance of the proposed technique are provided.