Mechanical design of the near-infrared arm of the Robert Stobie Spectrograph for SALT

Michael P. Smith, William P. Mason, Jeffrey P. Wong, Douglas P. Adler, Stephen Smee, Allen R. Rogers, Mark P. Mulligan, Jeffrey W. Percival, Andrew I. Sheinis, Donald J. Thielman, Marsha J. Wolf, Ian S. McLean (+2 others)
2010 Ground-based and Airborne Instrumentation for Astronomy III  
The Robert Stobie Spectrograph Near Infrared (RSS/NIR) upgrade for the Southern African Large Telescope (SALT) extends the capabilities of the visible arm of RSS into the NIR. The RSS/NIR instrument is at the prime focus of SALT. It is a versatile spectrograph with broadband imaging, spectropolarimetric, and Fabry-Perot imaging capabilities. The multiple modes and prime focus location introduce interesting engineering considerations. The spectrograph has an ambient temperature collimator,
more » ... (-40ºC) dispersers and camera and a cryogenic detector. Many of the mechanisms are required to operate within the cooled and cryogenic environments. The RSS/ NIR upgrade includes the following mechanisms; an active flexure compensating fold mirror, a filter exchange mechanism, a Volume Phase Holographic VPH grating exchange and rotation mechanism, an etalon inserter, a beam splitter inserter, an articulating camera, internal camera focus and a cutoff filter exchange wheel. This paper gives an overview of the mechanical design and focuses on some of the unique testing and prototyping tasks.
doi:10.1117/12.857394 fatcat:v36cy24vszfdfcvjupk6suju5e