Configurable slit unit versus slit mask exchanger trade study for the TMT wide field optical spectrometer

Alastair W. Heptonstall; David Andersen; Warren Skidmore; Reston Nash; Jason Fucik; Charles Steidel; Eric Peng; George Jacoby; John Miles

doi:10.1117/12.3020676

23 August 2024 Configurable slit unit versus slit mask exchanger trade study for the TMT wide field optical spectrometer

Alastair W. Heptonstall, David Andersen, Warren Skidmore, Reston Nash, Jason Fucik, Charles Steidel, Eric Peng, George Jacoby, John Miles

Author Affiliations +

Proceedings Volume 13099, Modeling, Systems Engineering, and Project Management for Astronomy XI; 130992S (2024) https://doi.org/10.1117/12.3020676
Event: SPIE Astronomical Telescopes + Instrumentation, 2024, Yokohama, Japan

Conference Poster

Abstract

We present details of the recent trade study on design changes to the Wide Field Optical Spectrometer (WFOS) for the Thirty Meter Telescope (TMT)[1]. WFOS is planned as a first light instrument and will provide highly efficient imaging and multi-slit spectroscopy over the wavelength range 0.31 to 1µm across a field of view of 8.3 by 3 arcminutes. The existing baseline prior to the trade study used a laser cut metal slit mask at the focal plane to enable observation of ~50 to 80 objects simultaneously. The masks would be cut in advance of observing and installed in a cassette, allowing a mechanism to select the mask and move it into place at the focal plane. Each multi-object observation requires a dedicated mask, with a more general single long slit mask remaining in the cassette permanently. The configurable slit unit (CSU) is an alternative approach, and a design that has previously been used in MOSFIRE and FORS. A CSU uses multiple knife edges mounted on computer-controlled bars to create and position slits at the focal plane. In the case of WFOS the CSU will be capable of creating 96 separate slits with the ability to reconfigure them on the fly to adapt to seeing conditions or to respond to targets of opportunity. We detail here the decision criteria, design, and science case analysis used by the WFOS team to decide to change the baseline design of WFOS to incorporate a CSU.

(2024) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

Alastair W. Heptonstall, David Andersen, Warren Skidmore, Reston Nash, Jason Fucik, Charles Steidel, Eric Peng, George Jacoby, and John Miles "Configurable slit unit versus slit mask exchanger trade study for the TMT wide field optical spectrometer", Proc. SPIE 13099, Modeling, Systems Engineering, and Project Management for Astronomy XI, 130992S (23 August 2024); https://doi.org/10.1117/12.3020676

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