MIRAC2: a mid-infrared array camera for astronomy

MIRAC2 was built for ground-based astronomy at Steward Observatory, University of Arizona and Harvard-Smithsonian Center for Astrophysics. It utilizes a Rockwell HF-16 128 X 128 arsenic-doped silicon blocked-impurity-band hybrid array with a wavelength range of 2 to 28 micrometers operating in a liquid helium-cooled cryostat at 5K. Reflective optics, and externally actuated detector and pupil slides provide a variety of magnification and focal ratio settings without opening the cryostat. Nominal settings at the NASA IRTF and UKIRT give diffraction-limited imaging with .34 and .27 arcsec/pixel, respectively. The sensitivity on the IRTF at 11.7 micrometers , 10 percent bandwidth filter, chop-nod, source in one beam, 1 sigma, one minute total time is 25 mJ/arcsec surface brightness and 43 mJy point source.