A fast calculation algorithm for the charge transfer loss in CCDs

Charge transfer loss due to deep level traps in CCDs is a common phenomenon. In single-photon counting CCDs for X-ray detection, the charge loss results in a degradation of spectroscopic resolution. The transfer loss of a signal depends on various parameters like temperature, number of transferred charges, number of charges in the preceding signals and the elapsed time between these signals. Each signal has to be corrected individually with respect to these parameters. An algorithm based on first principles of capture and emission, that allows a fast determination of the transfer loss is presented. The model was tested on calibration data of an X-ray pn-CCD of the EPIC consortium for XMM. The model describes the experimental data very well.