The rocket experiment demonstration of a soft x-ray polarimeter (REDSoX Polarimeter)
Date Issued
2017
Author(s)
Marshall, Herman L.
•
Schulz, Norbert S.
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Trowbridge Heine, Sarah N.
•
Heilmann, Ralf K.
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Günther, H. Moritz
•
Egan, Mark
•
Hellickson, Tim
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Schattenburg, Mark
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Chakrabarty, Deepto
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Windt, David L.
•
Gullikson, Eric M.
•
Ramsey, Brian D.
•
Weisskopf, Martin
•
•
•
Marscher, Alan
•
Jorstad, Svetlana
Abstract
The Rocket Experiment Demonstration of a Soft X-ray Polarimeter (REDSoX Polarimeter) is a sounding rocket instrument that can make the first measurement of the linear X-ray polarization of an extragalactic source in the 0.2-0.8 keV band as low as 10%. We employ multilayer-coated mirrors as Bragg reflectors at the Brewster angle. By matching the dispersion of a spectrometer using replicated optics from MSFC and critical angle transmission gratings from MIT to three laterally graded multilayer mirrors (LGMLs), we achieve polarization modulation factors over 90%. We present a novel arrangement of gratings, designed optimally for the purpose of polarimetry with a converging beam. The entrance aperture is divided into six equal sectors; pairs of blazed gratings from opposite sectors are oriented to disperse to the same LGML. The LGML position angles are 120 degrees to each other. CCD detectors then measure the intensities of the dispersed spectra after reflection and polarizing by the LGMLs, giving the three Stokes parameters needed to determine a source's linear polarization fraction and orientation. A current grant is funding further development to improve the LGMLs. Sample gratings for the project have been fabricated at MIT and the development team continues to improve them under separate funding. Our technological approach is the basis for a possible orbital mission
Coverage
UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XX
All editors
Siegmund, Oswald H.
Series
Volume
10397
Start page
103970K
Conferenece
UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XX
Conferenece place
San Diego, California, United States
Conferenece date
6-10 August, 2017
Issn Identifier
0277-786X
Ads BibCode
2017SPIE10397E..0KM
Rights
open.access
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