Toroidal Electric Field Effect and Non-Linear Effect on Electron Cyclotron Current Drive in the JT-60U
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Recent progress in the development of electron cyclotron heating⁄current drive systems in regard to power and pulse duration have allowed the extension of two normalized parameters (toroidal electric field E<sub>φ</sub> and wave power density p). In the extended regime, the conventional theory requires consideration of a distorted electron distribution function. The first validation of the ECCD theory in the extended regime having large E<sub>φ</sub> and p is presented. Linear calculation has a tendency to overestimate the EC driven current, as normalized parameters for E<sub>φ</sub> and p increase. While the EC driven current I<sub>EC</sub> obtained by a linearized Fokker-Planck calculation (1.1 MA) did not agree with the measured EC driven current (0.74 ± 0.06MA), non-linear calculation of the Fokker-Planck equation considering the effect of E<sub>φ</sub> (0.76 MA) shows close agreement with the experimental result. Calculations show that the decreasing effect of E<sub>φ</sub> on I<sub>EC</sub> was stronger than the increasing effect of p on I<sub>EC</sub> in the experiment.
- Journal of Plasma and Fusion Research
Journal of Plasma and Fusion Research 80(6), 511-515, 2004-06-25
The Japan Society of Plasma Science and Nuclear Fusion Research