Characterizing Dark Current of Two Novel Speedster-EXD550 X-Ray Hybrid CMOS Detectors

For space-based X-ray applications, silicon hybrid CMOS detectors (HCDs) offer many advantages over CCDs such as faster readout rates and in-pixel circuitry. Achieving low noise in X-ray applications of HCDs helps to achieve better energy resolution, so understanding their dark current and read noise is a high priority. Dark current is a type of noise resulting from thermal energy exciting electrons in the detector. It is temperature dependent, so cooling the detector is the best way to minimize its effects. Cooling detectors is costly for CubeSats, so it is important to characterize dark current at the temperatures the detectors will see in orbit. The BlackCAT CubeSat is a Coded Aperture Telescope that will search the soft X-ray sky for high-energy astronomical transients. It is a 6U CubeSat mission using an array of four Speedster-EXD550 X-ray HCDs. Here, we analyze the dark current of two Speedster-EXD550s.