Optimisation of the thickness of the moderator for positron annihilation process study in Ar gas

  • Toshitaka Oka
  • Yosuke Sano
  • Yasushi Kino
  • Tsutomu Sekine
Regular Article
Part of the following topical collections:
  1. Topical issue: Electron and Positron Induced Processes

Abstract

To investigate the deceleration and annihilation processes of positron in noble gas, we attempted to optimise the thickness of the positron moderator. The results of the decreasing trend of free positron intensity and ortho-positronium intensity with the thickness, and the annihilation rate suggest that the energy of almost all the positrons passed through the metal foils was much above the positronium formation threshold of 9 eV. Total thickness of 0.1 g cm-2 of the moderator and the Ar gas was required to stop almost all the positron in Ar gas.

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Copyright information

© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Toshitaka Oka
    • 1
    • 2
  • Yosuke Sano
    • 2
  • Yasushi Kino
    • 2
  • Tsutomu Sekine
    • 1
  1. 1.Institute for Excellence in Higher Education, Tohoku UniversitySendaiJapan
  2. 2.Department of ChemistryTohoku UniversitySendaiJapan

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