title: A Rocket-Borne Liquid Helium-Cooled Infrared Telescope. II: Photoconductive Detectors.
abstract: In the absence of a thermal radiation background, it is possible to obtain a very high responsivity with far ir extrinsic photoconductive detectors. Using a low noise liquid helium-cooled preamplifier, we have obtained an NEP of 10(-14) W Hz(-(1/2)) for Ge: Ga at 100 micro in an instrument designed for rocket ir astronomy. The limiting noise factor appears to be generation recombination noise due to thermal excitation of other impurities present in the germanium.
authors.forename: P D
authors.initials: PD
authors.lastname: Feldman
authors.forename: D P
authors.initials: DP
authors.lastname: McNutt