Event Pileup in Charge Coupled Devices

The problem of event pileup in single photon counting CCD cameras (e.g., in the X-ray regime) is discussed and a solution to the problem is proposed. The resulting pileup equation includes the effects of grade migration and presents itself as a non-linear modification to the standard integral equation used by forward-folding spectral fitting programs. The effectiveness of the model is demonstrated by its application to the moderately piled zeroth order data obtained by the Chandra X-Ray Observatory for the quasar S5 0836+7104.