| Original Articles |
|
|
|
|
Modification of Boundary Fluctuations by LHCD in the HT-7 Tokamak |
| SONG Mei;WAN Bao-Nian;XU Guo-Sheng;LING Bi-Li |
| Institute of Plasma Physics, Chinese Academy of Sciences, P O Box 1126, Hefei 230031 |
|
| Cite this article: |
|
SONG Mei, WAN Bao-Nian, XU Guo-Sheng et al 2003 Chin. Phys. Lett. 20 865-868 |
|
|
|
Abstract Measurements of boundary fluctuations and fluctuation driven electron fluxes have been performed in ohmic and lower hybrid current drive enhanced confinement plasma using a graphite Langmuir probe array on HT-7 tokamak. The fluctuations are significantly suppressed and the turbulent fluxes are remarkably depressed in the enhanced plasma. We characterized the statistical properties of fluctuations and the particle flux and found a non-Gaussian character in the whole scrap-off layer with minimum deviations from Gaussian in the proximity of the velocity shear layer in ohmic plasma. In the enhanced plasma the deviations in the boundary region are all reduces obviously. The fluctuations and induced electron fluxes show sporadic bursts asymmetric in time and the asymmetry is remarkably weakened in the lower hybrid current driving (LHCD) phase. The results suggest a coupling between the statistical behaviour of fluctuations and the turbulent flow.
|
| Keywords:
52.35.Ra
52.25.Fi
52.55.Fa
52.25.Gj
52.50.Sw
|
|
|
Published: 01 June 2003
|
|
| PACS: |
52.35.Ra
|
(Plasma turbulence)
|
| |
52.25.Fi
|
(Transport properties)
|
| |
52.55.Fa
|
(Tokamaks, spherical tokamaks)
|
| |
52.25.Gj
|
(Fluctuation and chaos phenomena)
|
| |
52.50.Sw
|
(Plasma heating by microwaves; ECR, LH, collisional heating)
|
|
|
|
|
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
