Quasisteady high-confinement reversed shear plasma with large bootstrap current fraction under full noninductive current drive condition in JT-60U.
A quasisteady reversed shear plasma with a large bootstrap current fraction ( approximately 80%) has been obtained for the first time in the JT-60U tokamak. The shrinkage of reversed shear region was suppressed by the bootstrap current peaked at the internal transport barrier (ITB) layer and the ITBs at a large radius were sustained, which, by combination with an H-mode edge pedestal, resulted in a high confinement or 2.2 times the H-mode scaling for 6 times energy confinement time or 2.7 s. Furthermore, a full noninductive current drive was obtained by the bootstrap current and the beam driven current.
Fujita
T
T
Japan Atomic Energy Research Institute, Naka Fusion Research Establishment, Naka-machi, Ibaraki-ken, Japan.
Ide
S
S
Kamada
Y
Y
Suzuki
T
T
Oikawa
T
T
Takeji
S
S
Sakamoto
Y
Y
Koide
Y
Y
Isayama
A
A
Hatae
T
T
Kubo
H
H
Higashijima
S
S
Naito
O
O
Shirai
H
H
Fukuda
T
T