Compton polarimetry revisited

Abstract

I compute the average polarisation asymmetry from the Klein-Nishina differential cross section on free electrons at rest. As expected from the expression for the asymmetry, the average asymmetry is found to decrease like the inverse of the incident photon energy asymptotically at high energy. I then compute a simple estimator of the polarisation fraction that makes optimal use of all the kinematic information present in an event final state, by the use of "moments" method, and I compare its statistical power to that of a simple fit of the azimuthal distribution. In contrast to polarimetry with pair creation, for which I obtained an improvement by a factor of larger than two in a previous work, here for Compton scattering the improvement is only of 10-20 %.

10 pages, 3 figures, accepted for publication in NIM A

References in corpus (8)

• Polarization of the Crab pulsar and nebula as observed by the Integral/IBIS telescope
• Polarimetry of cosmic gamma-ray sources above e+e- pair creation threshold
• An Electron-Tracking Compton Telescope for a Survey of the Deep Universe by MeV gamma-rays
• GRIPS - Gamma-Ray Imaging, Polarimetry and Spectroscopy
• Compton Imaging of MeV Gamma-Rays with the Liquid Xenon Gamma-Ray Imaging Telescope (LXeGRIT)
• Calibration of the Gamma-RAy Polarimeter Experiment (GRAPE) at a Polarized Hard X-Ray Beam
• Polarimetry in the hard X-ray domain with INTEGRAL SPI
• Analysis of the Data from Compton X-ray Polarimeters which Measure the Azimuthal and Polar Scattering Angles

Cited by in corpus (2)

• HARPO, a gas TPC active target for high-performance $\gamma$-ray astronomy; demonstration of the polarimetry of MeV $\gamma$-rays converting to $e^{+}{e}^{-}$ pair
• Compton Telescopes for Gamma-ray Astrophysics