New advanced operational regime on the W7-AS stellarator.
A promising new plasma operational regime on the Wendelstein stellarator W7-AS has been discovered. It is extant above a threshold density and characterized by flat density profiles, high energy and low impurity confinement times, and edge-localized radiation. Impurity accumulation is avoided. Quasistationary discharges with line-averaged densities n(e) to 4 x 10(20) m(-3), radiation levels to 90%, and partial plasma detachment at the divertor target plates can be simultaneously realized. Energy confinement is up to twice that of a standard scaling. At B(t) = 0.9 T, an average beta value of 3.1% is achieved. The high n(e) values allow demonstration of electron Bernstein wave heating using linear mode conversion.
McCormick
K
K
Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching, Germany. Kent.McCormick@ipp.mpg.de
Grigull
P
P
Burhenn
R
R
Brakel
R
R
Ehmler
H
H
Feng
Y
Y
Gadelmeier
F
F
Giannone
L
L
Hildebrandt
D
D
Hirsch
M
M
Jaenicke
R
R
Kisslinger
J
J
Klinger
T
T
Klose
S
S
Knauer
J P
JP
König
R
R
Kühner
G
G
Laqua
H P
HP
Naujoks
D
D
Niedermeyer
H
H
Pasch
E
E
Ramasubramanian
N
N
Rust
N
N
Sardei
F
F
Wagner
F
F
Weller
A
A
Wenzel
U
U
Werner
A
A