Lifetime estimation of a time projection chamber x-ray polarimeter

Hill, J. E.; Black, J. K.; Brieda, Lubos; Dickens, Patsy L.; Garcia, Kristina Montt de; Hawk, Douglas L.; Hayato, Asami; Jahoda, K.; Mohammed, Jelila S.

doi:10.1117/12.2024724

Cited by 11 publications

(10 citation statements)

References 11 publications

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“…Figure 7 Electron capture coefficient for three different configurations. Red is the life test unit, a small proportional counter detector, consisting of almost all the same materials as the GEMS polarimeter, installed in an off-the-shelf conflat vacuum chamber previously reported in Hill et al 4 Blue represents measurements with the flight detector unit (PDR design with no epoxy) that has a lifetime of more than two years without the use of a getter. Green points are initial measurements taken with the narrow-gap detector over 26 days and extrapolated forwards as an initial estimate.…”

Section: Narrow-gap Polarimeter Lifetime Testsmentioning

confidence: 99%

“…A detailed description of the analysis and measurements of the lifetime of the GEMS polarimeter can be found in Hill et al 4 Detector performance degrades as materials in the sealed enclosure outgas impurities that pick up the primary electrons thus impacting the gain and energy resolution of the system and eventually the polarization sensitivity. A useful measure of this process is given by the electron capture co-efficient, α which is determined from measuring GEM gain versus drift distance, x, at a given X-ray energy, according to:…”

Section: Narrow-gap Polarimeter Lifetime Testsmentioning

confidence: 99%

“…The design implemented at the NASA Goddard Space Flight Center (GSFC) has been environmentally tested and shown to be at a technology readiness level -6 (TRL-6) 3 and have a lifetime of ~23 years 4 . Detailed measurements have been made at the Brookhaven National Synchrotron Light Source (NSLS) with a flight detector assembled for the GEMS mission characterizing the sensitivity to polarized X-rays at 10 energies from 2.3 -8.0 keV at five detector positions 2 .…”

Section: Introductionmentioning

confidence: 99%

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Design improvements and x-ray performance of a time projection chamber polarimeter for persistent astronomical sources

et al. 2014

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The 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 lifetime 4 , 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.

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Section: Narrow-gap Polarimeter Lifetime Testsmentioning

confidence: 99%

Section: Narrow-gap Polarimeter Lifetime Testsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Design improvements and x-ray performance of a time projection chamber polarimeter for persistent astronomical sources

et al. 2014

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“…• Keith Jahoda [66] pointed me to a study [67] that demonstrated the feasability of a TPC detector with a lifetime on the 20 year scale for the GEMS project;…”

Section: Notes Added In Proofmentioning

confidence: 99%

HARPO: a TPC as a gamma-ray telescope and polarimeter

et al. 2014

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“…There is good prospects that the rapid degradation of the TPC gas quality that the EGRET spark chambers have undergone and that motivated a refill per year, is well under control with TPC proportional gas amplifiers [58,59].…”

Section: γ-Ray Polarimetry With Pairs: Techniquesmentioning

confidence: 99%

γ-Ray polarimetry with conversions to e+e− pairs: Polarization asymmetry and the way to measure it

Gros

Bernard

2017

Astroparticle Physics

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We revisit the measurement of the polarization fraction, P , and the measurement of the polarization angle of partially linearly-polarized gamma rays using their conversion to e + e − pairs in the field of a nucleus. We show that an inappropriate definition of the azimuthal angle, ϕ, used to reference the orientation of the final state degrades the precision of the measurement of P , by comparison to the optimal case where the bisector angle of the electron and of the positron momenta is used. We then focus on the lowest part of the energy spectrum, below ≈ 10 MeV, where a large part of the statistics lie for a cosmic source. We obtain the value of the polarization asymmetry, A, of pair conversion at threshold and we show that in the case where the correct expression is used for ϕ, the measured value of A tends to the limit.

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Lifetime estimation of a time projection chamber x-ray polarimeter

Cited by 11 publications

References 11 publications

Design improvements and x-ray performance of a time projection chamber polarimeter for persistent astronomical sources

Design improvements and x-ray performance of a time projection chamber polarimeter for persistent astronomical sources

HARPO: a TPC as a gamma-ray telescope and polarimeter

γ-Ray polarimetry with conversions to e+e− pairs: Polarization asymmetry and the way to measure it

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