61st Annual Meeting of the APS Division of Plasma Physics
Volume 64, Number 11
Monday–Friday, October 21–25, 2019;
Fort Lauderdale, Florida
Session CO7: MF: Gyrokinetics and Edge Physics
2:00 PM–4:12 PM,
Monday, October 21, 2019
Room: Grand F
Chair: MJ Pueschel, IFS
Abstract ID: BAPS.2019.DPP.CO7.9
Abstract: CO7.00009 : The Effect of External Driven Sources on the Edge Radial Electric Field
(Author Not Attending)
Preview Abstract
Abstract
Author:
Guoliang XIAO
(Southwestern Insititute of Physics, Chengdu, China)
Intensive work has been conducted to investigate the role of E$\mathrm{×}$B
flow shearing for L-H transition. It has been shown that this flow shear is
responsible for the turbulence suppression. An effective method to achieve
the external active control of E$\mathrm{×}$B velocity shear is required to
accelerate the transition process. Recently, a body of work has pointed out
that the turbulence regulation by shear flow also play an important role
during ELM mitigation. At present, active control techniques for the radial
electric profile is the electrode immersed in the device or the outer
magnetic perturbation coils. In the HL-2A H mode plasma, different methods
have been found to modify the radial electric profile, namely,
E$\mathrm{×}$B velocity shear, such as SMBI, LBO impurity seeding and LHCD.
This paper reports the obvious modification and different effects of these
external source input on the E$\mathrm{×}$B velocity shear. And the
discrepancy is due to the external source input modified the different term
of the E$\mathrm{×}$B velocity shear. LHCD modified the ion diamagnetic term
${\mathrm{\nabla }E}_{r}^{\nabla P_{i}}$ of the $\gamma_{E\mathrm{×}B}$ due
to the non-resonant collisional absorption of the high
N$_{\mathrm{//\thinspace }}$components of lower hybrid wave at the plasma
edge. On the other hand, different from the experiment with LHCD, it has
been observed that change of $\gamma_{E\mathrm{×}B}$ with LBO impurity
seeding and SMBI is attributed to the poloidal velocity component
$\mathrm{\nabla }E_{r}^{V_{\theta }}$ and the toroidal velocity component
${\mathrm{\nabla E}}_{\mathrm{r}}^{\mathrm{V}_{\mathrm{\varphi
}}}\mathrm{\nabla }\mathrm{E}_{\mathrm{r}}^{\mathrm{V}_{\mathrm{\theta
}}}$ due to the localized cooling effect. These results indicate that the
edge flow shear can be regulated to achieve L-H transition and ELM
mitigation by alternating proper external source input.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2019.DPP.CO7.9