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2.7 Shutter and Newell Mask

The four positions of this mechanism are

  1. shutter closed
  2. shutter open
  3. top half of beam masked
  4. bottom half of beam masked.
The shutter may be activated either by the CCD computer directly or the telescope computer running the echelle program depending upon switch settings on the instrument. The Newell mask shutter positions may be used to focus the collimator if desired, but must be done manually at the present time. The proper collimator setting will usually be set by the instrument assistant, leaving only the CCD to be focused. The collimator setting depends on which optics are installed, filters used, and the spectrograph alignment.
Fri June 9 08:00:00 MST 1995