The ~(55)Fe X-Ray Energy Response of Mercury Cadmium Telluride Near-Infrared Detector Arrays

摘要

A technique involving ~(55)Fe X-rays provides a straightforward method to measure the response of a detector. The detector's response can lead directly to a calculation of the conversion gain (e~-ADU~(-1)), as well as aid detector design and performance studies. We calibrate the ~(55)Fe X-ray energy response and pair production energy of HgCdTe using 8 HST WFC3 1.7 pm flight grade detectors. The results show that each Kct X-ray generates 2273 ± 137 electrons, which corresponds to a pair-production energy of 2.61 ± 0.16 eV. The uncertainties are dominated by our knowledge of the conversion gain. In future studies, we plan to eliminate this uncertainty by directly mea_suring conversion gain at very low light levels.