14 February 2003 Sensitivity of a photoelectric x-ray polarimeter for astronomy: the impact of the gas mixture and pressure
Author Affiliations +
Abstract
A Micropattern detector in the focus of a grazing incidence telescope is nowadays the most powerful tool to perform a sensitive and reliable measurement of the linear polarization of celestial X-ray sources. The actual implementation of such a completely new device results from a trade-off of various factors and can provide a break-through increase of sensitivity with respect to traditional instrumental approaches. The sensitivity depends on the effective area of the optics and the modulation factor and efficiency of the detector. The latter strongly depends on the filling gas through various factors, including the absorption probability, the length of track versus the pixel size, the blurring introduced by the lateral diffusion during the drift. We discuss the impact of the choice of the filling gas on the sensitivity and on the operative band of the instrument, while the noble gases drive the efficiency, the organic quenching gases impact both in reducing the scattering and producing most straight tracks and on reducing diffusion. Some design solution are discussed both for a low energy oriented and high energy oriented polarimeters.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Luigi Pacciani, Luigi Pacciani, Enrico Costa, Enrico Costa, Giuseppe Di Persio, Giuseppe Di Persio, Marco Feroci, Marco Feroci, Paolo Soffitta, Paolo Soffitta, Luca Baldini, Luca Baldini, Ronaldo Bellazzini, Ronaldo Bellazzini, Alessandro Brez, Alessandro Brez, Nicolas Lumb, Nicolas Lumb, Gloria Spandre, Gloria Spandre, } "Sensitivity of a photoelectric x-ray polarimeter for astronomy: the impact of the gas mixture and pressure", Proc. SPIE 4843, Polarimetry in Astronomy, (14 February 2003); doi: 10.1117/12.459275; https://doi.org/10.1117/12.459275
PROCEEDINGS
12 PAGES


SHARE
RELATED CONTENT

Stellar x-ray polarimeter and the Spectrum-X-Gamma mission
Proceedings of SPIE (February 15 1994)
Micropattern gas detector for x-ray polarimetry
Proceedings of SPIE (February 14 2003)
Cylindrical proportional counter for x-ray polarimetry
Proceedings of SPIE (February 01 1991)
First light from a very large area pixel array for...
Proceedings of SPIE (June 15 2006)
A burst chasing x-ray polarimeter
Proceedings of SPIE (September 13 2007)

Back to Top