Bochum 1998 – scientific programme

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HK: Hadronen und Kerne

HK 56: Postersitzung

HK 56.32: Poster

Wednesday, March 18, 1998, 17:00–19:00, Foyer

A New Microwave Dissociator for the HERMES Polarized Gas Target — •Norbert Koch and Erhard Steffens — Physikalisches Institut der Universität Erlangen–Nürnberg, Erwin–Rommel–Str.1,
D–91058 Erlangen.

In order to increase the intensity of the HERMES target source for polarized hydrogen and deuterium atoms, a new type of hydrogen dissociator has been developed and optimized in a seperate teststand. In contrast to the present 13.56 MHz radio frequency dissociator this new device is based on the coupling of a 2.45 GHz surface wave to the hydrogen discharge via a so called Waveguide Surfatron plasma source [1]. Measurements of the degree of dissociation show an improvement in the atomic fraction of a factor between 1.5 to 2.0 in comparison to the present dissociator for both hydrogen and deuterium as well as reproducible and long term stable operation. A test installation of the new dissociator in the HERMES target source during the 97/98 winter shutdown will show the impact of its higher dissociation efficiency on the achievable target density.

[1] M. Moisan et al, J. Phys. E: Sci. Instrum. 20, 1356 (1987).

Supported in part by the BMBF under grant number 06MR567TP2 and 057ER12P2, by DESY Hamburg, the MPI Heidelberg and the FZ Jülich.