Toroidal Electric Field Effect and Non-Linear Effect on Electron Cyclotron Current Drive in the JT-60U

抄録

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_φ 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_φ and p is presented. Linear calculation has a tendency to overestimate the EC driven current, as normalized parameters for E_φ and p increase. While the EC driven current I_EC 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_φ (0.76 MA) shows close agreement with the experimental result. Calculations show that the decreasing effect of E_φ on I_EC was stronger than the increasing effect of p on I_EC in the experiment.