Speaker
Mr
Liming Yu
(China)
Description
It is important to carry out the experimental studies for the fishbone instabilities, which are relevant for understanding alpha particle dynamics in burning plasmas. The e-fishbone frequency jump related to the redistribution of the energetic electrons has been observed on Tore Supra with LHCD, which is important for the energetic particle losses. In this paper, the e-fishbone frequency jump phenomena with high power on axis ECRH on HL-2A will be reported. The new results are different from the phenomena on Tore-Supra, because the trapped particle is dominated in this case.
The frequency spectra of the soft x-ray shows that the frequency of the fluctuations is about 5 kHz in the low ECRH power and increases to about 8 kHz when the power increases to 1.2MW. The chirping mode during ECRH has been identified as the fishbone instability induced by energetic electrons in the previous investigation in the device. It is interested to study the nature of the frequency jump phenomena in the high power ECRH. The frequency jump can be observed, when ECRH power increases to about 0.7MW. The frequency jump phenomena appear within about 25ms periodically. The frequency jumps between 8 kHz and 15 kHz, when the power is 1.2MW. The evidence of the changes of poloidal wave number can be obtained by the results of the tomography of two soft x ray arrays. The results show that the modes are located q=1 surface and poloidal wave numbers are m=1 or 2. That means the mode changes between m/n=1/1 and m/n=2/2.
It is very important to understand the mechanism driven by both the passing particles and trapped particles, comparing with the e-fishbone features during LHCD. And it is also very important to study the instability with high power electron heating and the confinement of the energetic particles.
Country or International Organization of Primary Author
China
Primary author
Mr
Liming Yu
(China)
Co-authors
Prof.
Beibin Feng
(Southwestern Institute of Physics)
Prof.
Jiaqi Dong
(Southwestern Institute of Physics)
Prof.
Jun Rao
(Southwestern Institute of Physics)
Dr
Jun Zhou
(Southwestern Institute of Physics)
Prof.
Longwen Yan
(Southwestern Institute of Physics)
Prof.
Mei Huang
(Southwestern Institute of Physics)
Prof.
Qingwei Yang
(Southwestern Institute of Physics)
Dr
Shaoyong Chen
(College of Physical Science and Technology, Sichuan University)
Dr
Wei Chen
(Southwestern Institute of Physics)
Prof.
Xianming Song
(Southwestern Institute of Physics)
Dr
Xiaoquan Ji
(Southwestern Institute of Physics)
Prof.
Xuantong Ding
(Southwestern Institute of Physics)
Prof.
Xuru Duan
(Southwestern Institute of Physics)
Prof.
Yan Zhou
(Southwestern Institute of Physics)
Prof.
Yi Liu
(Southwestern Institute of Physics)
Prof.
Yuan Huang
(Southwestern Institute of Physics)
Dr
Yunbo Dong
(Southwestern Institute of Physics)
Dr
Zhongbing Shi
(Southwestern Institute of Physics)
