Berlin 2005 – wissenschaftliches Programm

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HK: Physik der Hadronen und Kerne

HK 22: Postersitzung

HK 22.86: Poster

Montag, 7. März 2005, 16:30–18:00, TU MA141

Radioactivity distribution in the MAFF beamline — •Jerzy Szerypo — Department für Physik, Universität München (LMU), D-85748 Garching, Germany

The MAFF facility (Munich Accelerator for Fission Fragments [1]) planned at the research reactor FRM-II in Munich is dedicated to produce, cool and accelerate high-intensity neutron-rich radioactive beams. The primary radioactive beam consists of fission fragments, which result from bombarding a uranium target by the thermal neutrons emerging from the reactor. The fragments are produced in the target/ion source unit. Part of the nuclides are ionized (1+) and accelerated to 30 keV energy. A considerable portion of fission fragments will leave the target without being ionized. In order to retain the noble radioactive gases in a well-shielded place and also to provide good vacuum conditions in the reactor beam tube, helium-cooled cryopanels (T=15 K) will be installed close to the ion source. This contribution is concerned with simulating the properties of the MAFF beamline cryopumping system. The calculations are performed with the help of the computer program MOVAK3D [2]. This program simulates, in 3 dimensions, the trajectories of single particles (atoms, molecules) in an arbitrary vacuum system, in a Monte Carlo approach. Preliminary results show that the fraction of non-ionized radioactivity at the experimental area amounts to about 10-7 only.

[1] D. Habs et al., Nucl. Instr. Meth. B204 (2003) 739 [2] G. Class, Report 4292, Institut IRS, Kernforschungszentrum Karlsruhe GmbH (1987)