Turbulence at the transition to the high density H-mode in Wendelstein 7-AS 
plasmas

Basse, N. P.; Zoletnik, S.; Bäumel, S.; Endler, M.; Hirsch, M.; McCormick, K.; Werner, A.

Item

ITEM ACTIONSEXPORT

Add to Basket

Local TagsRelease HistoryDetailsSummary

Released

Journal Article

Turbulence at the transition to the high density H-mode in Wendelstein 7-AS plasmas

MPS-Authors

/persons/resource/persons108602

Bäumel, S.
Experimental Plasma Physics 3 (E3), Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons109027

Endler, M.
Stellarator Scenario Development (E5), Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons109397

Hirsch, M.
W7-X: Physics (PH), Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons109914

McCormick, K.
Stellarator Scenario Development (E5), Max Planck Institute for Plasma Physics, Max Planck Society;
W7-AS, Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons110781

Werner, A.
W7-X: Physics (PH), Max Planck Institute for Plasma Physics, Max Planck Society;

External Resource

No external resources are shared

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

Fulltext (public)

There are no public fulltexts stored in PuRe

Supplementary Material (public)

There is no public supplementary material available

Citation

Basse, N. P., Zoletnik, S., Bäumel, S., Endler, M., Hirsch, M., McCormick, K., et al. (2003). Turbulence at the transition to the high density H-mode in Wendelstein 7-AS plasmas. Nuclear Fusion, 43, 40-48.

Cite as: https://hdl.handle.net/11858/00-001M-0000-0027-22FE-9

Abstract

Recently a new improved confinement regime was found in the Wendelstein 7-AS (W7-AS) stellarator (Renner H. et al 1989 Plasma Phys. Control. Fusion 31 1579). The discovery of this high density high confinement mode (HDH-mode) was facilitated by the installation of divertor modules. In this paper, measurements of short wavelength density fluctuations in the HDH-mode using collective scattering of infrared light are presented. These measurements will be contrasted to fluctuations during normal confinement operation (NC-mode). The autopower spectra of the measurements show a consistent increase of the fluctuation level associated with the transition from NC- to HDH-mode. Correlation calculations on a 20 mus timescale between magnetic and density fluctuations lead to the result that the fluctuations are correlated in NC- but not in HDH-mode. Finally, a comparative analysis between the enhanced D-alpha H-mode (EDA H-mode) found in the Alcator C-Mod tokamak and the HDH-mode in W7-AS is carried out.