Proton damage effects in an EEV CCD imager

A three-phase CCD (charge-coupled device) has been irradiated by 40-MeV protons up to a fluence of 3*10/sup 8/ p/cm/sup 2/. Dark charge spikes appeared, but these were smaller than those previously reported for virtual-phase CCDs. Dark charge maps were obtained at several temperatures. The larger spikes showed erratic temperature behavior, whereas the smaller ones decreased in size as the temperatures decreased, but at a rate slower than the mean dark charge level. Possible mechanisms are discussed. The present study arose from the need to consider the performance of CCD-based star trackers used as part of the attitude measurement and control system of the West German Roentgen Satellite (ROSAT) X-ray astronomy mission. >