ENERGY AND PARTICLE CONFINEMENT IN WENDELSTEIN VII-A - NI PLASMAS
Experiments have shown, that the heating of ions and electrons by the neutral beams is collisional. Therefore the measured high ion temperatures in the centre require an ion heat conductivity about an order of magnitude smaller than the plateau value. Preliminary calculations indicate that such a reduced heat conductivity is compatible with radial electric fields derived from the observed poloidal rotation of impurity ions. At outer radii the anomalous electron heat conductivity found in OH discharges gives a good description of the electron energy transport; in the center an additional transport mechanism (probably independent of "DEL"-perpendicular T-e) is needed which could be due to resonant magnetic surface effects. Within the assumptions of the model used, electron heat conduction and the smaller impurity radiation are the main energy loss mechanisms. Particle confinement behaves similar to the energy confinement. Calculations indicate that again radial electric fields might be necessary to understand the observed T-p approximately equal 100 ms.
Bibliographic Reference: 5TH INTERNATIONAL WORKSHOP ON STELLARATORS, SCHLOSS RINGBERG, BAVARIA (GERMANY), SEPT. 24-28, 1984 VOL. I PP. 219-231, EUR 9618 EN (1985) FS, VOL. I AND VOL. II, 787 P., BFR 3500 (BOTH VOLUMES), EUROFFICE, LUXEMBOURG, POB 1003
Record Number: 1989124119800 / Last updated on: 1987-01-01
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