Fast Readout of the Skipper CCD for Astronomy and Quantum Imaging

The Skipper is a special type of charge-coupled device (CCD) that allows pixel measurements with sub-electron noise levels due to its non-destructive readout operation. Over the last decade, these sensors have been used as particle detectors on a variety of experiments, such as the direct detection of galactic dark matter and neutrino experiments. Skipper CCD achieves low-noise by reading multiple times, and sequentially, the pixel charge packet, which translates to longer readout times. This becomes a limiting factor for those applications that require sub-electron detection and faster readout speeds. A novel analysis method for reducing the total pixel readout time is presented in this work. The method relies on analyzing the time-domain properties of the video signal including the clock feedthroughs and their shapes to optimize the clock transitions that define the pixel. The analysis technique is experimentally demonstrated using a standard scientific detector and also with a Skipper CCD with single photon sensitivity. In both cases the sensors are operated and readout using the Low Threshold Acquisition (LTA) controller with an updated firmware for faster clock sequencing. A good compromise between noise performance and total readout time was achieved. This will allows the use of the Skipper CCD and/or the LTA for astronomy, quantum imaging, and other applications that require faster readout times than previous uses of the sensor and the controller.