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Applied Physics A

, Volume 74, Supplement 1, pp s295–s297 | Cite as

Intense positron source at the Munich research reactor FRM-II

  • C. Hugenschmidt
  • G. Kögel
  • R. Repper
  • K. Schreckenbach
  • P. Sperr
  • B. Strasser
  • W. Triftshäuser

Abstract.

The principle and the design of the in-pile positron source at the new Munich research reactor FRM-II are presented. Absorption of high-energy prompt γ-rays from thermal neutron capture in 113Cd generates positrons by pair production. For this purpose, a cadmium cap is placed inside the tip of the inclined beam tube SR11 in the neutron field of the reactor, where an undisturbed thermal neutron flux up to 2×1014 n cm-2 s-1 is expected. At this position the flux ratio of thermal to fast neutrons will be better than 104. Monte Carlo calculations showed that a mean capture rate in cadmium between 4.5 and 6.0×1013 n cm-2 s-1 can be expected. Inside the cadmium cap a structure of platinum foils is placed for converting γ-radiation into positron–electron pairs. The heated foils also act as positron moderators to generate monoenergetic positrons. After acceleration to 5 keV a positron beam is formed by electric lenses and guided by magnetic fields. In the primary positron beam an intensity up to 1010 slow positrons per second is expected.

PACS: 07.77.Ka; 25.40.Lw; 78.70.Bj 

Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  • C. Hugenschmidt
    • 1
  • G. Kögel
    • 2
  • R. Repper
    • 1
  • K. Schreckenbach
    • 1
  • P. Sperr
    • 2
  • B. Strasser
    • 1
  • W. Triftshäuser
    • 2
  1. 1.Technische Universität München, Lichtenbergstrasse, 85 747 Garching, GermanyDE
  2. 2.Institut für Nukleare Festkörperphysik, Universität der Bundeswehr München, 85 577 Neubiberg, GermanyDE

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