Simulation of photoelectric X-ray polarimetry and reconstruction of the photoelectron azimuthal angle

Abstract

Sensitive X-ray polarimetry in the keV energy range can be achieved by measuring the azimuthal angle distribution of emitted electrons after the photoelectric absorption of X-rays in a micropattern gas detector. However, the initial direction of the electron is not readily measurable due to the randomization of its motion during energy loss. By using the Geant4, Maxwell and Garfield packages, we simulated the detected electron tracks following photoelectric absorption, electron drift and diffusion in the gas, and proposed a technique capable of reconstructing the initial direction of the emitted photoelectron. The technique allows us to measure the angular modulation of flux predicted for a polarized X-ray beam. We calculated the modulation factors in 2-10 keV with a gas mixture of neon and CO2, and discussed how electron diffusion along the drift will dilute the track and suppress the modulation. These results are useful for the design of the X-ray polarimeter.

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“…The target proteins above have been proven to be key enzymes in metabolic pathways such as the synthesis of estrogen, synthesis of cholesterol, prostaglandin biosynthesis, and arachidonic acid metabolism. 41 42 43 44 This result indicates CWD may have the potential to regulate immune response mechanisms, which are usually the most important in the treatment of eczema and herpes zoster diseases.…”

IPS observation system for the Miyun 50 m radio telescope and its commissioning observation

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