Observation of confined current ribbon in JET plasmas.
We report the identification of a localized current structure inside the JET plasma. It is a field-aligned closed helical ribbon, carrying current in the same direction as the background current profile (cocurrent), rotating toroidally with the ion velocity (corotating). It appears to be located at a flat spot in the plasma pressure profile, at the top of the pedestal. The structure appears spontaneously in low density, high rotation plasmas, and can last up to 1.4 s, a time comparable to a local resistive time. It considerably delays the appearance of the first edge localized mode.
Solano
E R
ER
Laboratorio Nacional de Fusión, Asociación EURATOM-CIEMAT, 28040, Madrid, Spain.
Lomas
P J
PJ
Alper
B
B
Xu
G S
GS
Andrew
Y
Y
Arnoux
G
G
Boboc
A
A
Barrera
L
L
Belo
P
P
Beurskens
M N A
MN
Brix
M
M
Crombe
K
K
de la Luna
E
E
Devaux
S
S
Eich
T
T
Gerasimov
S
S
Giroud
C
C
Harting
D
D
Howell
D
D
Huber
A
A
Kocsis
G
G
Korotkov
A
A
Lopez-Fraguas
A
A
Nave
M F F
MF
Rachlew
E
E
Rimini
F
F
Saarelma
S
S
Sirinelli
A
A
Pinches
S D
SD
Thomsen
H
H
Zabeo
L
L
Zarzoso
D
D