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Design Improvements and X-Ray Performance of a Time Projection Chamber Polarimeter for Persistent Astronomical SourcesThe design of the Time-Projection Chamber (TPC) Polarimeter for the Gravity and Extreme Magnetism Small Explorer (GEMS) was demonstrated to Technology Readiness Level 6 (TRL-6)3 and the flight detectors fabricated, assembled and performance tested. A single flight detector was characterized at the Brookhaven National Laboratory Synchrotron Light Source with polarized X-rays at 10 energies from 2.3-8.0 keV at five detector positions. The detector met all of the GEMS performance requirements. Lifetime measurements have shown that the existing flight design has 23 years of lifetime4, opening up the possibility of relaxing material requirements, in particular the consideration of the use of epoxy, to reduce risk elsewhere. We report on design improvements to the GEMS detector to enable a narrower transfer gap that, when operated with a lower transfer field, reduces asymmetries in the detector response. In addition, the new design reduces cost and risk by simplifying the assembly and reducing production time. Finally, we report on the performance of the narrow-gap detector in response to polarized and unpolarized X-rays.
Document ID
20160005185
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Hill, Joanne E. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Black, J. Kevin (Adnet Systems, Inc. Greenbelt, MD, United States)
Emmett, Thomas J. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Enoto, Teruaki (Institute of Physical and Chemical Research Saitama, Japan)
Jahoda, Keith M. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Kaaret, Philip (Iowa Univ. Iowa City, IA, United States)
Nolan, David S. (SGT, Inc. Greenbelt, MD, United States)
Tamagawa, Toru (Institute of Physical and Chemical Research Saitama, Japan)
Date Acquired
April 19, 2016
Publication Date
July 25, 2014
Publication Information
Publication: Proceedings of SPIE
Volume: 9144
ISSN: 0277-786X
ISBN: 0277-786X
Subject Category
Instrumentation and Photography
Report/Patent Number
GSFC-E-DAA-TN28529
Funding Number(s)
CONTRACT_GRANT: NNG06EO90A
CONTRACT_GRANT: NNG12CR290
CONTRACT_GRANT: NNG12PL17C
CONTRACT_GRANT: USP-SMP-12-14
Distribution Limits
Public
Copyright
Other
Keywords
GEMS
X-ray Polarimetry
Gas Electron Multiplier
Gravity and Extreme Magnetism Small explorer