Speaker
Min Jiang
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P4.1090.pdf
Interaction between magnetic island, plasma perpendicular flow and
turbulence in HL-2A ohmic plasmas
M. Jiang1, W.L. Zhong1, Y. Xu2, Z.B. Shi1, W. Chen1, X.Q. Ji1, X.T. Ding1, Z.C. Yang1, P.W.
Shi1, A.S. Liang1, J. Wen1, J. Q. Li1, Y. Zhou1, Y.G. Li1, D.L. Yu1, Y. Liu1, Q.W. Yang1 and M.
Xu1
1 Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, People’s Republic of
China
2 Institute of Fusion Science, School of Physical Science and Technology, Southwest Jiaotong
University, Chengdu 610031, People’s Republic of China
Corresponding author: jiangm@swip.ac.cn
The multi-scale physics such as the interaction between large scale MHD modes and turbulence
were reported to play a crucial role in the transport regulation in the core plasma [1, 2] and the
interaction between sheared zonal flow and turbulence was considered to be the key ingredient
for the low-to-high confinement mode transition [3, 4]. In this work, we present the first
experimental observations of the interaction between magnetic island, plasma perpendicular
flow and turbulence in the presence of the naturally rotating m/n = 2/1 tearing mode in the HL-
2A ohmic plasmas using a hopping Doppler backward scattering reflectometer system, which
provides direct experimental evidence for the simulations. It has been observed that across the
O-point cut the perpendicular flow is near zero at the center of the island and strongly enhanced
around the boundary of the island, resulting in a large increase of the flow shear in the outer
half island, while across the X-point cut the flow is almost flat in the whole island region.
Meanwhile it was found that the density fluctuations drop near the O-point region while
elevated at the X-point region, which is in agreement with the gradient drive of the turbulence.
The results indicate that both the perpendicular flow and the density fluctuation level are
modulated by the naturally rotating tearing mode near the island boundary. The cross-
correlation between the perpendicular flows and the oscillating electron temperature further
reveals that the modulation of the perpendicular flow occurs mainly inside and in the vicinity
of the island.
[1] Bardóczi L. et al 2016 Phys. Rev. Lett. 116 215001
[2] Choi M.J. et al 2017 Nucl. Fusion 57 126058
[3] Kim E.J. and Diamond P.H. 2003 Phys. Rev. Lett. 90 185006
[4] Schmitz L. et al 2012 Phys. Rev. Lett. 108 155002
