Study of cadmium zinc telluride (CZT) radiation detector modules under moderate and long-term variations of temperature and humidity

A gamma camera, assembled from radiation imaging modules based on cadmium zinc telluride (CZT), has been studied under moderate and long-term variations of temperature (15degC to 40degC) and humidity (10% to 70%). Over one year we acquired energy spectra from radiation sources and we measured the photo-peak position and energy resolution. We observe that the camera remains within the desired performance specifications. We conclude that the CZT sensor material is stable over the temperature and humidity range tested and that the CZT sensors retain their energy resolution of 5.4 keV FWHM at 122 keV and keep the photo-peak position within a margin of plusmn1 keV.