Temperature controller keeps IR detector at 8°K

摘要

Sensitive infrared array detectors must operate at a low temperature to avoid thermally generated dark current throughout the photoconductive elements. This requirement is particularly true for SiAs array detectors, which need cooling to near liquid-helium temperatures. Furthermore, the sensitivity of these detectors can be temperature-dependent. The optimal operating temperature for a long-wavelength IR camera is about 8°K. This temperature must remain constant despite changes in the radiation level falling on the array, in the liquid helium level as it boils away, and in the orientation of the Dewar flask.