Accurately simulating gain and clock-induced charge production in the EMCCD gain register

An EMCCD will be used for faint companion detection in the Roman Telescope’s coronograph instrument. As the EM gain increases, the chance of clock-induced charge (CIC) production in the gain register increases, which affects the intended multiplication of charge. I have improved the EMCCD detector simulator used for the Roman Telescope, emccd_detect, so that it accounts for this effect. I demonstrate through maximum likelihood estimation that EMCCD data conform better to the modified probability distribution which accounts for this effect. The use of the modified distribution would in principle improve EMCCD calibration and the accuracy of signal extraction from a frame. I discuss the implementation of this as well as other high-gain phenomena in emccd_detect and demonstrate the enhanced accuracy of the simulator.