title: Synchronization of Geodesic Acoustic Modes and Magnetic Fluctuations in Toroidal Plasmas.
abstract: The synchronization of geodesic acoustic modes (GAMs) and magnetic fluctuations is identified in the edge plasmas of the HL-2A tokamak. Mesoscale electric fluctuations (MSEFs) having components of a dominant GAM, and m/n=6/2 potential fluctuations are found at the same frequency as that of the magnetic fluctuations of m/n=6/2 (m and n are poloidal and toroidal mode numbers, respectively). The temporal evolutions of the MSEFs and the magnetic fluctuations clearly show the frequency entrainment and the phase lock between the GAM and the m/n=6/2 magnetic fluctuations. The results indicate that GAMs and magnetic fluctuations can transfer energy through nonlinear synchronization. Such nonlinear synchronization may also contribute to low-frequency zonal flow formation, reduction of turbulence level, and thus confinement regime transitions.
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: K J
authors.initials: KJ
authors.lastname: Zhao
authors.affiliation: Research Institute for Applied Mechanics, Kyushu University, Kasuga, Kasuga koen 6-1, 816-8580, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nagashima
authors.affiliation: Center for Momentum Transport and Flow Organization, University of California at San Diego, California, San Diego 92093, USA.
authors.forename: P H
authors.initials: PH
authors.lastname: Diamond
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.|Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027, China.
authors.forename: J Q
authors.initials: JQ
authors.lastname: Dong
authors.affiliation: National Institute for Fusion Science, Toki 509-5292, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Itoh
authors.affiliation: Research Institute for Applied Mechanics, Kyushu University, Kasuga, Kasuga koen 6-1, 816-8580, Japan.
authors.forename: S-I
authors.initials: SI
authors.lastname: Itoh
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: L W
authors.initials: LW
authors.lastname: Yan
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: J
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Research Institute for Applied Mechanics, Kyushu University, Kasuga, Kasuga koen 6-1, 816-8580, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Fujisawa
authors.affiliation: Research Institute for Applied Mechanics, Kyushu University, Kasuga, Kasuga koen 6-1, 816-8580, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Inagaki
authors.affiliation: Research Institute for Applied Mechanics, Kyushu University, Kasuga, Kasuga koen 6-1, 816-8580, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kosuga
authors.affiliation: Research Institute for Applied Mechanics, Kyushu University, Kasuga, Kasuga koen 6-1, 816-8580, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Z X
authors.initials: ZX
authors.lastname: Wang
authors.affiliation: School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: L
authors.initials: L
authors.lastname: Wei
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Huang
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: D L
authors.initials: DL
authors.lastname: Yu
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: W Y
authors.initials: WY
authors.lastname: Hong
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Ji
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: X M
authors.initials: XM
authors.lastname: Song
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: Q W
authors.initials: QW
authors.lastname: Yang
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: X T
authors.initials: XT
authors.lastname: Ding
authors.affiliation: Southwestern Institute of Physics, P.O. Box 432, Chendu 610041, China.
authors.forename: X R
authors.initials: XR
authors.lastname: Duan