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Measurements Of Dark Current In A Ccd Imager During Light Exposures, Ralf Widenhorn, Ines Hartwig, Justin Charles Dunlap, Erik Bodegom

Physics Faculty Publications and Presentations

Thermal excitation of electrons is a major source of noise in Charge-Coupled Device (CCD) imagers. Those electrons are generated even in the absence of light, hence the name dark current. Dark current is particularly important for long exposure times and elevated temperatures. The standard procedure to correct for dark current is to take several pictures under the same condition as the real image, except with the shutter closed. The resulting dark frame is later subtracted from the exposed image. We address the question of whether the dark current produced in an image taken with a closed shutter is identical to …