Speaker
Mr
Jun Cheng
(China)
Description
A quasi-period electrostatic oscillation with 2-3 kHz is observed using Langmuir probe array during slow L-H transition in edge plasma of HL-2A Tokomak. This low frequency oscillation radially propagates inwards with 0.3-0.6 km/s inside the separatrix about 3-8 mm, and it appears on potential, density, electron pressure and Reynolds stress gradients. The dPe/dr fluctuation amplitude can reach 30-40%. The dRs/dr is prior to Er fluctuation about pi/2, indicating the existence of nonlinear interaction between them. In near SOL, this low frequency oscillation also appears in potentials, Er and density fluctuation, suggesting a significant correlation among them at edge and near SOL plasma. This quasi-period oscillation might be correlated with mean flow or low frequency zonal flow, and the latter might set a condition for the former developing, implying a competitive process between them. The competition characterized by a quasi-period oscillation seems to determine the L-H transition.
Collaboration (if applicable, e.g., International Tokamak Physics Activities)
Xu Min
Country or International Organization of Primary Author
China
Primary author
Mr
Jun Cheng
(Southwestern Institute of Physics)
Co-authors
Dr
A Di Liu
(University of Science and Technology of China)
Mr
De Feng Kong
(Southwestern Institute of Physics)
Prof.
Jia Qi Dong
(Southwestern Institute of Physics)
Mr
Jun Cheng
(China)
Prof.
Kai Jun Zhao
(Southwestern Institute of Physics)
Dr
Min Xu
(CMTFO & CER & MAE Department, UCSD)
Prof.
Qing Wei Yang
(Southwestern Institute of Physics)
Dr
Tao Lan
(University of Science and Technology of China)
Prof.
Wen Yu Hong
(Southwestern Institute of Physics)
Prof.
Xian Ming Song
(Southwestern Institute of Physics)
Prof.
Xu Ru Duan
(Southwestern Institute of Physics)
Prof.
Xuan Tong Ding
(Southwestern Institute of Physics)
Mr
Yong Gao Li
(Southwestern Institute of Physics)
Prof.
Yong Liu
(Southwestern Institute of Physics)
Mr
Zhi Hui Huang
(Southwestern Institute of Physics)
