No abstract

The Low Resolution Imaging Spectrometer is designed for use at the Cassegrain focus of the Keck 10-meter telescope. It provides the capability of acquiring low resolution (R = 1000 to 5000) digital spectra, as well as 6 x 8 arc-minute moderately high spatial resolution (4.65 pixels/arc-second) direct images. Spectroscopy can be carried out with single slits which are 3 arc-minutes long. In addition punched multi-slits can also be employed which allow for the acquisition of at least forty spectra simultaneously.Since the instrument is designed to be as efficient as possible, it is a double spectrograph, with a dichroic splitting the blue and red light into separate optical paths after the collimator. Only the red side has been constructed thus far. With a 2048 by 2048 thinned Tektronix CCD as the detector the total efficiency of the red side at the peak of the grating blaze is predicted to be nearly 40%.Results of the commissioning observing runs will be described.