TY - GEN

T1 - The rocket experiment demonstration of a soft x-ray polarimeter (REDSoX Polarimeter)

AU - Marshall, Herman L.

AU - Schulz, Norbert S.

AU - Trowbridge Heine, Sarah N.

AU - Heilmann, Ralf K.

AU - Günther, H. Moritz

AU - Egan, Mark

AU - Hellickson, Tim

AU - Schattenburg, Mark

AU - Chakrabarty, Deepto

AU - Windt, David L.

AU - Gullikson, Eric M.

AU - Ramsey, Brian D.

AU - Weisskopf, Martin

AU - Tagliaferri, Gianpiero

AU - Pareschi, Giovanni

AU - Marscher, Alan

AU - Jorstad, Svetlana

N1 - Publisher Copyright: © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

PY - 2017

Y1 - 2017

N2 - 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.

AB - 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.

KW - Astronomy

KW - Grating

KW - Mirror

KW - Multilayer

KW - Polarimeter

KW - X-ray

UR - http://www.scopus.com/inward/record.url?scp=85033472637&partnerID=8YFLogxK

U2 - 10.1117/12.2274107

DO - 10.1117/12.2274107

M3 - Conference contribution

AN - SCOPUS:85033472637

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XX

A2 - Siegmund, Oswald H.

PB - SPIE

T2 - UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XX 2017

Y2 - 6 August 2017 through 8 August 2017

ER -