Berlin 2005 – wissenschaftliches Programm
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P: Plasmaphysik
P 23: Poster: Magnetischer Einschluß 3, Staubige Plasmen 2, Astrophysikalische Plasmen 1
P 23.24: Poster
Dienstag, 8. März 2005, 16:30–18:30, Poster HU
Ion heating during magnetic reconnection as measured with laser induced fluorescence — •Albrecht Stark1, Jan Egedal2, Will Fox2, Olaf Grulke1, and Thomas Klinger1 — 1Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, EURATOM Assoziation — 2Massachusetts Institute of Technology, Plasma Science and Fusion Center
Observations in space and laboratory plasmas suggest magnetic reconnection as a mechanism for ion heating and formation of non Maxwellian ion velocity distribution functions (IVDF). The breaking and reconnecting of field lines permits the release of magnetic energy to ion kinetic energy. However, the underlying mechanisms remain unclear. Periodically driven reconnection is investigated in the Versatile Toroidal Facility (VTF) at the MIT Plasma Science and Fusion Center. Poloidal and toroidal magnetic field coils form a poloidal cusp-field with an toroidal guiding field. Reconnection is driven via a third toroidal solenoid. In this paper laser-induced fluorescence measurements of the IVDF parallel to the X-line during magnetic reconnection are presented. A time resolved analysis yields the evolution of the IVDF within a reconnection cycle. It is demonstrated, that the ion temperature strongly increases during a reconnection cycle. Furthermore, a large non-thermal (beam) ion population occurs at the maximum reconnection rate, supposedly due to an inflow of plasma from outer regions of the cusp field. It is suggested, that beam-plasma instability significantly contributes to the observed ion heating.