Radiation Tolerance of High-Resistivity LBNL CCDs

Thick, fully-depleted p-channel charge-coupled devices (CCDs) have been developed at the Lawrence Berkeley National Laboratory (LBNL). These CCDs have several advantages over conventional n-channel CCDs, including enhanced quantum efficiency and reduced fringing at near-infrared wavelengths, a small point spread function, and improved radiation tolerance. Here we report results from the irradiation of CCDs with 12.5 and 55 MeV protons at the LBNL 88-Inch Cyclotron. These studies indicate that the CCDs still perform well after irradiation, even in the parameters in which significant degradation is expected: charge transfer efficiency, dark current, and isolated hot pixels. As expected, the radiation tolerance of the LBNL CCDs is significantly improved over conventional n-channel CCDs currently employed in space-based telescopes such as the Hubble Space Telescope (HST).