Fishbone activity in experimental advanced superconducting tokamak neutral beam injection plasma

Repetitive fishbones near the trapped ion procession frequency were observed for the first time in the neutral beam injection high confinement plasmas in Experimental Advanced Superconducting Tokamak (EAST) tokamak, and diagnosed using a solid-state neutral particle analyzer based on a compact silic...

Full description

Saved in:
Bibliographic Details
Published in:Physics of plasmas 2015-12, Vol.22 (12)
Main Authors: Xu, Liqing, Zhang, Jizong, Chen, Kaiyun, Hu, Liqun, Li, Erzhong, Lin, Shiyao, Shi, Tonghui, Duan, Yanmin, Zhu, Yubao
Format: Article
Language:English
Subjects:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM INJECTION
Crashes
DIAMAGNETISM
Energetic particles
HT-7U TOKAMAK
IONS
Neutral beams
NEUTRAL PARTICLE ANALYZERS
Neutral particles
NONLINEAR PROBLEMS
Photodiodes
PLASMA
PLASMA CONFINEMENT
PLASMA INSTABILITY
Plasma physics
ROTATING PLASMA
Rotating plasmas
SAWTOOTH OSCILLATIONS
SILICON
SOFT X RADIATION
Soft x rays
SPATIAL RESOLUTION
Superconductivity
TIME RESOLUTION
Tokamak devices
TOMOGRAPHY
TRAPPING
Twisting
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Repetitive fishbones near the trapped ion procession frequency were observed for the first time in the neutral beam injection high confinement plasmas in Experimental Advanced Superconducting Tokamak (EAST) tokamak, and diagnosed using a solid-state neutral particle analyzer based on a compact silicon photodiode together with an upgraded high spatial-temporal-resolution multi-arrays soft X-ray (SX) system. This 1/1 typical internal kink mode propagates in the ion-diamagnetism direction with a rotation speed faster than the bulk plasma in the plasma frame. From the SX measurements, this mode frequency is typical of chirping down and the energetic particle effect related to the twisting mode structure. This ion fishbone was found able to trigger a multiple core sawtooth crashes with edge-2/1 sideband modes, as well as to lead to a transition from fishbone to long lived saturated kink mode to fishbone. Furthermore, using SX tomography, a correlation between mode amplitude and mode frequency was found. Finally, a phenomenological prey–predator model was found to reproduce the fishbone nonlinear process well.
ISSN:1070-664X
1089-7674
DOI:10.1063/1.4939020