Viscous damping of rotation in Wendelstein 7-AS

Differential Rotation in Neutron Stars: Magnetic Braking and Viscous Damping

Diffferentially rotating stars can support significantly more mass in equilibrium than nonrotating or uniformly rotating stars, according to general relativity. The remnant of a binary neutron star merger may give rise to such a “hypermassive” object. While such a star may be dynamically stable against gravitational collapse and bar formation, the radial stabilization due to differential rotati...

On Viscous Damping and Rotation in Low-Shear Stellarators

one of the main results of the Wendelstein 7-AS stellarator (major radius 2 m, average plasma radius 0' l8 m, magnetic field 2.5 T' low shear) is the achievement of the H-mode confinement in ECRand NBl-heated plasmas. The features of the H-mode are similar to those of a tokamak: reduction of the Ho-emission, onset of poloidal rotation anda30vo improvement of the energy confinement time, which i...

Spatial distribution of turbulence in the Wendelstein 7-AS stellarator

In this paper measurements of short wavelength electron density fluctuations using collective scattering of infrared light are presented. The Wendelstein 7-AS (W7-AS) stellarator (Renner H et al 1989 Plasma Phys. Control. Fusion 31 1579) and the diagnostic are briefly described. A series of plasma discharges with reproducible confinement transitions was created by ramping up the plasma current....

Island divertor experiments on the Wendelstein 7-AS stellarator

A promising new operational regime on the Wendelstein stellarator W7-AS has been discovered, fulfilling the conditions of optimal core behavior in combination with edge parameters suitable for successful divertor scenarios. This regime, the high density H-mode (HDH), displays no systematically evident mode activity, and is edge localized mode (ELM)-free. It is extant above a power-dependent thr...

Wendelstein 7-X and fusion