Focus and translation mechanism for the Gemini Multiobject Spectrograph (GMOS)

摘要

Abstract: GMOS is the general-purpose optical spectrograph for the Gemini telescope. It is to be mounted at the Cassegrain focus and has been designed from the outset to have open-loop active correction for the effects of instrumental flexure. This is done by moving the CCD detector mosaic in two axes to counter the image drift due to flexure. GMOS is also focused by moving the detector and the three axis mechanism to achieve these motions is described here. The mechanism also provides the necessary thermal isolation for the cooled CCD and is driven by stepping motors outside the CCD vacuum vessel. !4