Speaker
Liqing Xu
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.1032.pdf
Kink Mode Study in EAST High 𝜷𝑷 Plasma
Liqing Xu, Yi Yuan, Wei Shen and Liqun Hu
Institute of plasma physics, CAS (ASIPP)
Two types of kink modes, fishbone and long-lived mode are experimentally and numerically
studied at EAST tokamak. In high 𝛽$ plasma, sawtooth instability was replaced by a saturated
1/1 internal kink mode which either manifests itself as a periodical burst energetic ion related
fishbone or as a long-lived mode which is associated to the core safety factor at 𝑞& ~1. The
present of those1/1 internal modes are beneficial to the sustainment of hybrid scenario with
extended regions of low-magnetic shear profile and 𝑞& ~1, because of that they can expel high-
Z impurity and can make flux pumping. The mechanism responsible for the flux pumping
caused by kink mode was numerically in nonlinear 3D magnetohydrodynamic simulations
using the M3D code. Furthermore, M3D+K code hybrid simulation shows a good agreement
to the fishbone activity in EAST. Sawtooth crash replaced by 1/1 dominated helical mode and
bursting of many toroidal harmonics (n=2 to n=7) in hybrid scenario are also confirmed by
M3D simulation.
Figure 1. Long-lived mode in EAST low-magnetic shear profile and q& ~1 hybrid plasma.
