Radiation effects on astrometric CCDs at low operating temperatures

Emission times of proton-induced traps and optical spot profiles have been measured at temperatures around -110/spl deg/C for large format charge-coupled devices (CCDs), representative of those to be used for the Gaia mission. There are at least seven trap species involved, with emission times in the range 0.3 /spl mu/s to 130 s and there is evidence for charge re-trapping by fast traps. Trap filling using a charge injection gate is discussed.