[Table of Contents]

Plasma and Fusion Research

Volume 5, S2014 (2010)

Regular Articles


Experimental Study of Turbulence and Zonal Flow in Edge Plasmas of the HL-2A Tokamak
Jiaqi DONG1,4), Kaijun ZHAO1), Longwen YAN1), Wenyu HONG1), Changxuan YU2), Akihide FUJISAWA3), Jun QIAN1), Jun CHENG1), Adi LIU2), Tao LAN2), Hailin ZHAO2), Defeng KONG2), Yi LIU1), Yuan HUANG1), Qiang LI1), Xianming SONG1), Qingwei YANG1), Xuantong DING1), Xuru DUAN1) and Yong LIU1)
1)
Southwestern Institute of Physics, P. O. Box 432, Chengdu, China
2)
Department of Modern Physics, University of Science and Technology of China, Hefei, China
3)
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
4)
Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou, China
(Received 7 December 2009 / Accepted 4 March 2010 / Published 10 December 2010)

Abstract

Measurements with a three dimensional set of Langmuir probe arrays have unambiguously demonstrated the coexistence of intensive low frequency zonal flows (LFZFs), geodesic acoustic modes (GAMs), low frequency fluctuations (LFFs) and high frequency ambient turbulence (HFAT) in the edge of HL-2A tokamak plasmas, by verifying the temporal and spatial characteristics of the electrostatic fluctuations. The intensity of the LFZFs is observed to increase and decrease with increases of ECRH power (∼ 300-700 kW) and safety factor q (∼ 3.5-6.2), respectively, and the intensity of the GAMs increases with the ECRH power as well as q. The radial wave number-frequency spectra of the LFZF show that the LFZF packets propagate outwards and inwards as equally likely events, while the GAM packets propagate predominantly outwards. The three wave coupling of the zonal flows, including the GAMs, and the LFFs with the HFAT is investigated in detail.


Keywords

turbulence, zonal flow, geodesic acoustic mode, coherency, Langmuir probe

DOI: 10.1585/pfr.5.S2014


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This paper may be cited as follows:

Jiaqi DONG, Kaijun ZHAO, Longwen YAN, Wenyu HONG, Changxuan YU, Akihide FUJISAWA, Jun QIAN, Jun CHENG, Adi LIU, Tao LAN, Hailin ZHAO, Defeng KONG, Yi LIU, Yuan HUANG, Qiang LI, Xianming SONG, Qingwei YANG, Xuantong DING, Xuru DUAN and Yong LIU, Plasma Fusion Res. 5, S2014 (2010).