Mainz 1997 – scientific programme
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P: Plasmaphysik
P 16: Magnetischer Einschluß IV
P 16.5: Talk
Wednesday, March 5, 1997, 12:15–12:30, P 10
Perturbative Particle Transport Studies in Wendelstein 7-AS — •J. P. T. Koponen1, T. Geist1, O. Dumbrajs2, and U. Stroth1 — 1Max-Planck-Institut für Plasmaphysik, EURATOM Association, 85748 Garching — 2Department of Technical Physics and Mathematics, Helsinki University of Technology, FIN-02150 Espoo, Finland
In W7-AS, the line-integrated electron density can be measured with high precision and high temporal resolution by means of the new multichannel-microwave interferometer. In order to study particle transport, the plasma density is perturbed by modulation of the gas feed to the plasma.
The transport coefficients are determined with two different and independent methods. First, the formalism based on linearization of the transport equation around equilibrium [1] is used. Here raw measured line-integrated electron densities in individual interferometer channels are employed as experimental input. Second, the full transport equation is solved by means of the transport code ASTRA [2]. In this case inverted experimental electron density distributions are used as input in the calculations. Particle transport coefficients obtained by the two methods are compared and effects of various plasma parameters on particle transport are studied. Of specific interest is the precence of a convective particle pinch.
[1] K. W. Gentle, O. Gehre, K. Krieger, Nucl. Fusion 32, 217 (1992)
[2] G.V. Pereverzev, et al., IPP 5/42, August 1991.