Far-infrared imaging array for SIRTF

We describe the design, construction, and performance of the 32 X 32 Ge:Ga imaging array being built at the University of Arizona for the Multiband Imaging Photometer for SIRTF (MIPS). The array will support a number of operational modes in the MIPS instrument including natural background-limited mapping at 70 micrometers , super-resolution observations at 70 micrometers , and spectral energy distribution measurements between 50 and 100 micrometers. The array is constructed in a modular manner using eight 4 X 32 pixel building blocks. To meet the sensitivity and stability requirements, the array must have excellent photometric repeatability, low noise, and robustness to the effects of the ionizing radiation environment in space. Key elements in attaining this level of performance are the Ge:Ga detectors materials and the cryogenic CRC-696 readout electronics. We present laboratory data for a 16 X 32 prototype of the array, and describe the plans for the construction of the qualification and flight units.