Toroidal varied-line-space (TVLS) gratings

Roger J. Thomas

doi:10.1117/12.460375

11 February 2003 Toroidal varied-line space (TVLS) gratings

Roger J. Thomas

Proceedings Volume 4853, Innovative Telescopes and Instrumentation for Solar Astrophysics; (2003) https://doi.org/10.1117/12.460375
Event: Astronomical Telescopes and Instrumentation, 2002, Waikoloa, Hawai'i, United States

Abstract

It is a particular challenge to develop a stigmatic spectrograph for EUV wavelengths since the very low normal-incidence reflectance of standard materials most often requires that the design be restricted to a single optical element which must simultaneously provide both re-imaging and spectral dispersion. This problem has been solved in the past by the use of toroidal gratings with uniform line-space rulings (TULS). A number of solar EUV spectrographs have been based on such designs, including SOHO/CDS, Solar-B/EIS, and the sounding rockets SERTS and EUNIS. More recently, Kita, Harada, and collaborators have developed the theory of spherical gratings with varied line-space rulings (SVLS) operated at unity magnification, which have been flown on several astronomical satellite missions. These ideas are now combined into a spectrograph concept that considers varied-line space grooves ruled onto toroidal gratings. Such TVLS designs are found to provide excellent imaging even at very large spectrograph magnifications and beam-speeds, permitting extremely high-quality performance in remarkably compact instrument packages. Optical characteristics of two solar spectrographs based on this concept are described: SUMI, proposed as a sounding rocket experiment, and NEXUS, proposed for the Solar Dynamics Observatory mission.

Citation Download Citation

Roger J. Thomas "Toroidal varied-line space (TVLS) gratings", Proc. SPIE 4853, Innovative Telescopes and Instrumentation for Solar Astrophysics, (11 February 2003); https://doi.org/10.1117/12.460375

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