MICS: A new Mid-Infrared Camera and Spectrometer for ground-based astronomy

We have developed the Mid-Infrared Camera and Spectrometer (MICS), which is optimized for ground-based observations in the N-band (7.6-13.6 mu m) atmo spheric window. The MICS has two observing capabilities: imaging and long s lit low-resolution spectroscopy. The major characteristics of the MICS are nearly diffraction-limited performance, both in imaging and in spectroscopy and the capability to take a spectrum of the whole N-band range with a spe ctral resolving power of 100. The MICS employs a state-of-the-art two-dimen sional array of 128 x 128 Si:As BIB detector, an aberration-corrected conca ve grating, and a high-speed readout system, which allows a compact design with high sensitivity. In this paper, we describe the design of MICS, including optics, cryogenics , and electronics, and its performance when used on the United Kingdom Infr ared Telescope (UKIRT). We also discuss sky noise in the N band and observa tional techniques for efficient mid-infrared observations.