Pulsed low energy positron system (PLEPS) at the Munich research reactor FRM II

Authors

  • W. Egger,

    Corresponding author
    1. Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg, Germany
    • Phone: + 49 (0)89 6004 3507, Fax: + 49 (0)89 6004 3295
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  • P. Sperr,

    1. Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg, Germany
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  • G. Kögel,

    1. Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg, Germany
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  • G. Dollinger

    1. Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg, Germany
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Abstract

Currently, the Munich pulsed low energy positron beam-system (PLEPS) is transferred to the high-intensity positron source (NEPOMUC) at the Munich research Reactor FRM II. We expect count-rates up to 106 cps. Several improvements to enhance the performance of the system have been implemented. Until now, PLEPS was employed exclusively for lifetime measurements. To enable also Doppler-broadening, coincident Doppler-broadening and AMOC experiments, two additional detector ports have been installed. An additional chopper allows to suppress pulses and, therefore, to extend the standard time window of 20 ns for precise measurements of longer lifetimes. The high event-rate supports the use of smaller scintillators. Consequently an improvement in time resolution is expected. Also envisaged is the use of new detector materials. Various measures to further reduce background from back-scattered positrons and a reduction of the beam diameter down to 1 mm will improve the overall performance of the system. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

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