Irradiation of the TC255P CCD by Fast Neutrons

The TC255P is a CCD manufactured by Texas Instruments. We propose to use it in the ATLAS end-cap muon alignment system. To find out if it could operate for ten years in the ATLAS radiation environment, we exposed four TC255Ps to fast neutrons. The doses delivered to the CCDs varied from one to three times the highest expected ten-year ATLAS dose in the end-cap. We observed that the dark current in the CCDs increased dramatically. But we observed no other forms of damage. We believe we understand the means by which neutron bombardment causes an increase in the dark current, and we have an empirical model that describes the progress of the damage with accumulated dose. This model predicts that, once we have made a number of simple changes to the image retrieval procedure, the TC255P will be able to operate for one hundred and thirty years in the ATLAS radiation environment.