Influence of the dynamic ergodic divertor on the density limit in TEXTOR.
A significant influence of the dynamic ergodic divertor (DED) on the density limit in TEXTOR has been found. In Ohmic discharges, where without DED detachment normally arises at the density limit, a MARFE (multifaceted asymmetric radiation from the edge) develops when the DED is operated in a static regime. The threshold of the MARFE onset in the neutral beam heated plasmas is increased by applying 1 kHz ac DED at the high-field side. The theoretical predictions based on the parallel energy balance taking poloidal asymmetries into account agree well with the experimental observation.
Liang
Y
Y
Institut für Plasmaphysik, Forschungszentrum Jülich GmbH, Association FZJ-EURATOM, 52425, Jülich Germany.
Koslowski
H R
HR
Kelly
F A
FA
Tokar
M Z
MZ
Loozen
X
X
Bertschinger
G
G
Biel
W
W
Finken
K H
KH
Jakubowski
M W
MW
Krämer-Flecken
A
A
Zimmermann
O
O
Lehnen
M
M
Sergienko
G
G
Wolf
R C
RC