Several companies have produced excellent CCD detectors with low noise, negligible dark current, and high charge-transfer efficiency. These devices are nearly ideal for astronomical observations, with the exception of low overall quantum efficiency (QE) and small imaging area. At Steward Observatory a post- manufacture CCD optimizing process has been developed with which commercially produced devices can be thinned for backside illumination, backside charging and antireflection coating. This procedure has now been demonstrated successfully on several devices manufactured at the Loral Aeronautronics Corporation. As a result of this success, we have undertaken a joint program with the National Optical Astronomy Observatories (NOAO) to custom-design two CCD detector formats for use in astronomical spectroscopy. Eighty-eight of each of these two devices have been manufactured (at NOAO's expense) with potentially 20% of astronomically useful quality. In this proposal we seek funding for the thinning, packaging, backside charging, antireflection coating, and implementation of several of these devices in the spectrographs of the two largest telescopes at the University of Arizona; the Multiple Mirror Telescope (MMT) on Mt. Hopkins and the 2.3 m telescope on Kitt Peak. These instruments are workhorse facility spectrographs routinely used by faculty, students, and visitors, and will benefit greatly by the improved spectral coverage, higher efficiency, flatter imaging surface, and lower noise of the new detectors. The MMT spectrograph in particular will for the first time have a two-dimensional detector available for blue and near-UV observations. This will open entirely new classes of observations which can be efficiently made with this large aperture telescope.
