| Abstract : | At TIFR we have designed and developed a Configurable Slit Unit (CSU) to generate a multi-slit configuration, a long slit, or an imaging aperture at the entrance focal plane of the Multi-Object Infrared Spectrometer (MOIS, Puravankara et al.) being designed for the Devasthal Optical Telescope. The CSU, consisting of 10 bars moving pair-wise in opposition, is capable of
creating up to 5 slits for spectroscopy at any location within the 86mmx86mm field of view of the spectrometer. Keeping in mind the requirements of near-infrared spectroscopic observations, the CSU is designed to operate at a temperature of 120 K. The regulated motion of the slit-bars was achieved using piezo-electric walkers and the slits are positioned with an accuracy better than 10 micron via a controlled position-sensitive loop. The modular nature of
the design makes the CSU scalable to accommodate a much larger number of slits. We shall present the results of the cryogenic and optical laboratory tests of the CSU prototype built at TIFR. |
