Configurable slit-mask unit of the multi-object spectrometer for infra-red exploration for the Keck telescope: integration and tests

Peter Spanoudakis; Laurent Giriens; Simon Henein; Leszek Lisowski; Aidan O'Hare; Emmanuel Onillon; Philippe Schwab; Patrick Theurillat

doi:10.1117/12.789017

18 July 2008 Configurable slit-mask unit of the multi-object spectrometer for infra-red exploration for the Keck telescope: integration and tests

Peter Spanoudakis, Laurent Giriens, Simon Henein, Leszek Lisowski, Aidan O'Hare, Emmanuel Onillon, Philippe Schwab, Patrick Theurillat

Author Affiliations +

Proceedings Volume 7018, Advanced Optical and Mechanical Technologies in Telescopes and Instrumentation; 70180I (2008) https://doi.org/10.1117/12.789017
Event: SPIE Astronomical Telescopes + Instrumentation, 2008, Marseille, France

Abstract

A Configurable Slit Unit (CSU) has been developed for the Multi-Object Spectrometer for Infra-Red Exploration (MOSFIRE) instrument to be installed on the Keck 1 Telescope on Mauna Kea, Hawaii. MOSFIRE will provide NIR multi-object spectroscopy over a field of view of 6.1' x 6.1'. The reconfigurable mask allows the formation of 46 optical slits in a 267 x 267 mm² field of view. The mechanism is an evolution of a former prototype designed by CSEM and qualified for the European Space Agency (ESA) as a candidate for the slit mask on NIRSpec for the James Webb Space Telescope (JWST). The CSU is designed to simultaneously displace masking bars across the field-of-view (FOV) to mask unwanted light. A set of 46 bar pairs are used to form the MOSFIRE focal plane mask. The sides of the bars are convoluted so that light is prevented from passing between adjacent bars. The slit length is fixed (5.1 mm) but the width is variable down to 200 μm with a slit positioning accuracy of ± 18 μm. A two-bar prototype mechanism was designed, manufactured and cryogenically tested to validate the modifications from the JWST prototype. The working principle of the mechanism is based on an improved "inch-worm" stepping motion of 92 masking bars forming the optical mask. Original voice coil actuators are used to drive the various clutches. The design makes significant use of flexure structures.

Citation Download Citation

Peter Spanoudakis, Laurent Giriens, Simon Henein, Leszek Lisowski, Aidan O'Hare, Emmanuel Onillon, Philippe Schwab, and Patrick Theurillat "Configurable slit-mask unit of the multi-object spectrometer for infra-red exploration for the Keck telescope: integration and tests", Proc. SPIE 7018, Advanced Optical and Mechanical Technologies in Telescopes and Instrumentation, 70180I (18 July 2008); https://doi.org/10.1117/12.789017

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available