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Multiple Etalon Systems for the Advanced Technology Solar TelescopeMultiple etalons systems are discussed that meet the 4-meter NSO/Advance Technology Solar Telescope (http://www.nso.edu/ATST/index.html) instrument and science requirements for a narrow bandpass imaging system. A multiple etalon system can provide an imaging interferometer working in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, and a wide-band and broad-band high-resolution imager. Specific dual and triple etalon configurations will be described that provides spectrographic passband of 2.0-3.5nm and reduces parasitic light levels to 1/10000 as required by precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like triple etalon system provides for spectral purity of 100 thousandths. The triple designs have the advantage of reducing the finesse requirement on each etalon, allowing much more stable blocking filters, and can have very high spectral purity. A dual-etalon double-pass Cavallini-like configuration can provide a competing configuration. This design can provide high contrast with only a double etalon. The selection of the final focal plan instrument will depend on a trade-off of the ideal instrument versus reality, the number of etalons, the aperture of etalons, the number of blocking filters the electronic control system and computer interfaces, the temperature control and controllers for the etalons and the electronics. The use of existing experience should provide significant cost savings. The heritage of use of etalons and multiple etalon systems in solar physics come from a number of observatories, which includes MSFC Solar Observatory (NASA), Sac Peak Observatory (NSO), and Kiepenheuer Institute for Solar Physics (Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will reply on the existing experience from these observatories.
Document ID
20020050379
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Gary, G. Allen
(NASA Marshall Space Flight Center Huntsville, AL United States)
Balasubramaniam, K. S.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Sigwarth, Michael
(NASA Marshall Space Flight Center Huntsville, AL United States)
Six, N. Frank
Date Acquired
August 20, 2013
Publication Date
January 1, 2002
Subject Category
Astronomy
Meeting Information
Meeting: Conference on Innovative Telescopes for Solar Astrophysics
Location: Paris
Country: France
Start Date: March 18, 2002
End Date: March 20, 2002
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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