https://doi.org/10.1051/epjconf/201715703018
Influence of Li conditioning on Lower Hybrid Current Drive efficiency in H-mode and L- mode plasmas on EAST
a CEA, IRFM, F-13108 Saint Paul-lez-Durance, France
b Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
* Corresponding author: marc.goniche@cea.fr
Published online: 23 October 2017
The lower hybrid current drive efficiency on the EAST tokamak is estimated on a large database of low loop voltage discharges (VL<120mV) covering the 2016 campaign starting with lithium-free plasma facing components and ending with strong cumulated deposition of lithium. The efficiency is found to vary in a wide range from 0.6 to 1.2×1019A.W-1.m-2. No deleterious effect of the density on the efficiency is found between 2.3 and 3.2×1019m-3. The high efficiency occurs after strong lithium evaporation. The low effective charge Zeff and the higher temperature <Te> of these discharges, can account for the high efficiency according to the expected scaling with Zeff and <Te>. Modelling with a ray-tracing code coupled to a Fokker-Planck solver supports this result, assuming that the fast electron transport is reduced in the zero loop voltage discharge with high efficiency.
© The authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
