Speaker
Taik Soo Hahm
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.1087.pdf
Residual Zonal Flows in Tokamaks in the Presence of Energetic Ions
T.S. Hahm1,∗ and Y.W. Cho1
1 Department of Nuclear Engineering, Seoul National University, Seoul, Republic of Korea
∗ tshahm@snu.ac.kr
Zonal flow, an axisymmetric potential fluctuation driven by turbulent Reynolds stress, plays
a key role in turbulence regulation with its flow shear. It gets reduced by collisionless process in
toroidal geometry, but to a non-zero value called the residual zonal flow level [1]. In this study,
we investigate the residual zonal flow in the presence of energetic ions using modern gyro-
kinetic approach[2]. We find that the residual zonal flow can be enhanced for the intermediate
radial wavelength range on the order of thermal ion banana width, due to the presence of slowing
down energetic ions.
References
[1] M.N.Rosenbluth and F.L. Hinton Phys. Rev. Lett. 80, 724 (1998)
[2] T.S. Hahm, Physics of Fluids 31, 2670 (1988)
