A study of hot pixel annealing in the Hubble Space Telescope Wide Field Camera 3 CCDs

Abstract

A Hubble Space Telescope Wide Field Camera 3 (WFC3) CCD detector was tested for radiation effects while operating at -83C. The goal of the experiment was to evaluate the introduction and annealing rates of hot pixels and to assess the dynamics of that process. The device was irradiated while cold and warmed to +30°C for a 4 hour soak, then cooled back down to -83°C. Hot pixel populations were tracked during warm up and cool down. The results showed that the hot pixels begin to anneal around -40°C and the anneal process was largely completed before the detector reached +30°C. It was also found that, although a large fraction of the hot pixels dropped below the threshold, they remained warmer than the remaining population.