Speaker
Guangzhou Hao
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P2.1053.pdf
Multi-branch resistive wall instabilities in a resistive plasma
G. Z. Hao1, S. X. Yang2, Y. Q. Liu3, Z. X. Wang2
1
Southwestern Institute of Physics, Chengdu, People’s Republic of China
2
Dalian University of Technology, Dalian People’s Republic of China
3
General Atomics, San Diego, California 92186-5608, USA
Most of the theory and the modelling efforts on the resistive wall mode (RWM)
instability are based on the ideal plasma assumption (i.e., without plasma resistivity).
Previous works shown that toroidal favorable average curvature (i.e. GGJ) effect associated
with the resistive layer has a stabilization effect on the RWM [1]. In this work, we apply the
full toroidal stability code MARS-F to investigate the GGJ effect on the RWM stability in a
toroidal resistive plasma. An important conclusion is that there are two instability branches of
the RWM, when the GGJ effect is taken into account as shown in Fig. 1. The behavior of
these two branches (both mode growth rate and mode real frequency) rather different while
varying both the Lundquist number and the toroidal plasma rotation frequency. However, only
one branch can be found when GGJ effect is excluded. Qualitatively similar results can be
obtained by numerically solving the RWM dispersion relation, which includes the resistive
layer physics associated with the GGJ effect.
Fig.1 The normalized growth rate (a) and real frequency (b) of resistive wall
mode versus the normalized plasma pressure β𝑁 with different choices of
Lundquist number S.
In order to successfully control RWM instability in high performance plasmas such as in
ITER, the possible multi-branches of RWM induced by non-ideal effects (e.g. resistivity
discussed in this work and the kinetic effect from thermal particles [3]) should be considered.
References
[1] Y. L. He, Y. Q. Liu, Y. Liu, G. Z. Hao, and A. K. Wang, Phys. Rev. Lett. 113, 175001 (2014).
[2] Y. L. He, Y. Q. Liu, Y. Liu, C. Liu, G. L. Xia, A. K. Wang, G. Z. Hao, L. Li, and S. Y. Cui, Phys. Plasmas 23,
012506 (2016).
[3] G. Z. Hao, S. X, Yang, Y. Q. Liu, Z. X. Wang, A. K. Wang, and H. D. He, Phys. Plasmas, {23, 062105
(2016)
