title: Spatiotemporal structures of edge limit-cycle oscillation before L-to-H transition in the JFT-2M tokamak.
abstract: In this Letter, we report analyses of spatiotemporal dynamics of turbulence and structure in the limit-cycle oscillation (LCO) that precedes an L-to-H transition. Zonal flows are not observed during LCO, and the oscillation is the periodic generations or decays of barrier with edge-localized mean flow. Oscillatory Reynolds stress is found to be too small to accelerate the LCO flow, by considering the dielectric constant in magnetized toroidal plasmas. Propagation of changes of the density gradient and turbulence amplitude into the core is also observed.
authors.affiliation: Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan. kobayashi@riam.kyushu-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Itoh
authors.forename: T
authors.initials: T
authors.lastname: Ido
authors.forename: K
authors.initials: K
authors.lastname: Kamiya
authors.forename: S-I
authors.initials: SI
authors.lastname: Itoh
authors.forename: Y
authors.initials: Y
authors.lastname: Miura
authors.forename: Y
authors.initials: Y
authors.lastname: Nagashima
authors.forename: A
authors.initials: A
authors.lastname: Fujisawa
authors.forename: S
authors.initials: S
authors.lastname: Inagaki
authors.forename: K
authors.initials: K
authors.lastname: Ida
authors.forename: K
authors.initials: K
authors.lastname: Hoshino