Displacement damage induce degradation of COTS array CCDs irradiated by neutron beams from a nuclear reactor

Abstract

The experiments of displacement damage effects on COTS array charge coupled devices (CCDs) induced by neutron irradiation from a nuclear reactor are presented. The charge transfer inefficiency (CTI), saturation output signal voltage (VS), dynamic range (DR), dark signal, and camera imaging quality versus neutron fluence are investigated. The degradation mechanisms of the CCDs irradiated by reactor neutron beams are also analyzed. The CTI increase due to neutron displacement damage appears to be proportional to displacement damage dose. The experiments show that VS degradation induced by neutron irradiation is much less than that induced by gamma irradiation. The dark images from the CCDs irradiated by neutrons are given to investigate dark signal degradation. The degradation forms and mechanisms of the camera imaging quality are very different between the reactor neutron displacement damage and the gamma total ionization dose damage. The three samples were exposed by 1MeV neutron-equivalent fluences of 1×1011, 5×1011, and 1×1012n/cm2, respectively. A sample was exposed by 1MeV neutron-equivalent fluences up to 2×1013n/cm2, and the CCD is a functional failure after irradiation.