  We report on the initial results of an experiment to determine the effects of
proton radiation damage on an X-ray hybrid CMOS detector (HCD). The device was
irradiated at the Edwards Accelerator Lab at Ohio University with 8 MeV
protons, up to a total absorbed dose of 3 krad(Si) (4.5 $\times$ 10$^9$
protons/cm$^2$). The effects of this radiation on read noise, dark current,
gain, and energy resolution are then analyzed. This exposure is the first of
several which will be used for characterizing detector performance at absorbed
dose levels that are relevant for imaging devices operating in a deep-space
environment.
