title: Quasisteady high-confinement reversed shear plasma with large bootstrap current fraction under full noninductive current drive condition in JT-60U.
abstract: 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.
authors.affiliation: Japan Atomic Energy Research Institute, Naka Fusion Research Establishment, Naka-machi, Ibaraki-ken, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fujita
authors.forename: S
authors.initials: S
authors.lastname: Ide
authors.forename: Y
authors.initials: Y
authors.lastname: Kamada
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Oikawa
authors.forename: S
authors.initials: S
authors.lastname: Takeji
authors.forename: Y
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Koide
authors.forename: A
authors.initials: A
authors.lastname: Isayama
authors.forename: T
authors.initials: T
authors.lastname: Hatae
authors.forename: H
authors.initials: H
authors.lastname: Kubo
authors.forename: S
authors.initials: S
authors.lastname: Higashijima
authors.forename: O
authors.initials: O
authors.lastname: Naito
authors.forename: H
authors.initials: H
authors.lastname: Shirai
authors.forename: T
authors.initials: T
authors.lastname: Fukuda