A NEAR-INFRARED CAMERA FOR LAS CAMPANAS OBSERVATORY

The optical, mechanical, and electronic designs of a multipurpose near-infrared (1.1-2.5-mu-m) camera built for Las Campanas Observatory are described. The camera is used on both the 2.5-m duPont and 1-m Swope Telescopes. A refractive all-spherical achromatic reimager incorporates three confocal discrete zooms which image onto a Rockwell HgCdTe (NICMOS2) 128 X 128 detector array. Although the instrument was designed primarily for imaging, we have included two experimental modes for future use - a low-resolution prism (R almost-equal-to 400) and a coronagraph. The optical design choices and procedures are described in some detail. The entire 0.6 m optical path resides at 77 K and is folded onto a 25.4 cm diameter dewar work surface. The instrument is remotely controlled by a Sun 386i graphics workstation via serial links to microprocessor-controlled motor-encoder packages and the array control electronics. Electronic designs suitable for use with a NICMOS2 array are given. The data are acquired and inspected using IRAF routines running under the UNIX multitasking environment. Initial performance results on camera optical quality and system sensitivity are given.