Kiel 2004 – scientific programme
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P: Plasmaphysik
P 15: Diagnostische Methoden IV
P 15.2: Fachvortrag
Wednesday, March 10, 2004, 15:45–16:05, H\"orsaal D
Laser induced fluorescence measurements during magnetic reconnection — •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
Magnetic reconnection is referred to as the breaking and recombination of field lines in magnetized plasmas. As magnetic reconnection permits the release of magnetic energy to ion thermal energy, it is believed to be the source of non-classical ion heating as observed, e.g., in solar flares. An experiment to study reconnection is the Versatile Toroidal Facility (VTF) at the MIT plasma science and fusion center. The toroidal vacuum chamber is immersed into sets of poloidal and toroidal magnetic field coils, forming a poloidal cusp-field and a toroidal guiding field. A third solenoid inside the torus acts as a drive for the reconnection. The plasma is generated by ECRH, providing electron and ion temperatures in the range Te ∼ 20eV, Ti ∼ 0.2eV and plasma densities of n ∼ 1017m−3. For determining the ion temperature during magnetic reconnection the full ion energy distribution function (IEDF) is measured by laser induced fluorescence. The diagnostics consists of a tunable high power diode laser (∼ 60mW cw). In order to investigate the effect of toroidal electric fields on the ion dynamics during magnetic reconnection, the laser is injected tangentially to the toroidal magnetic field. The results of the IEDF measurements at a single spatial point with and without reconnection are presented, and the implication for ion heating processes are discussed.