Circumvention of radiation-induced noise in CCD and CID imagers

Measurements of radiation sensitivity for interline-transfer charge-coupled devices (CCDs) and charge-injection devices (CIDs) from irradiation with high-energy photons (/sup 60/Co gamma rays and 3- to 5-MeV end-point bremsstrahlung) and 14-MeV neutrons are presented to establish imager susceptibility in such environments. Results from electronic clearing techniques designed for quick ( approximately=300 mu s for the CCDs and approximately=10 mu s for CIDs) removal (or dumping) of radiation-induced charge from prompt sources are discussed. Application of the techniques coupled with long-persistence (microsecond to millisecond) radiation-to-light converters for image retention are described. Typical data illustrating the effectiveness of charge clearing in removal of radiation noise are included for nanosecond-duration pulsed X-ray/ gamma -ray doses (50-mrad to 5-rad range) and microsecond-duration neutron fluences approaches 10/sup 8/ n/cm/sup 2/.<
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