https://doi.org/10.1051/epjconf/201920301004
Top Launch for Higher Off-axis Electron Cyclotron Current Drive Efficiency
1
General Atomics P.O. Box 85608, San Diego CA 92186-5608 USA
2
University of Science and Technology of China Hefei Anhui 230026 China
* Corresponding author: chenxi@fusion.gat.com
Published online: 25 March 2019
Efficient off-axis current drive is crucial for economic, steady-state tokamak fusion power plants. “Top Launch” electron cyclotron current drive (ECCD) is one promising method for driving strong off-axis current to achieve the desired broad current profile for the Advanced Tokamak regime. New simulations show that by launching the electron cyclotron (EC) waves downwards (or upwards) nearly parallel to the resonance plane with a large toroidal steering, higher current drive efficiency can be obtained at large radii owing to the large Doppler shift, wave-particle interactions on HFS of the plasma, and the long absorption path. Implementations on CFETR and DIII-D are simulated identifying clear benefits and optimal configurations. The design of a prototype test being installed on DIII-D is presented, which will experimentally validate whether top launch ECCD can be an improved efficiency current drive technique for future fusion reactors.
© The Authors, published by EDP Sciences, 2019
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