title: Ion gyroscale fluctuation measurement with microwave imaging reflectometer on KSTAR.
abstract: Ion gyroscale turbulent fluctuations with the poloidal wavenumber kθ∼ 3 cm-1have been measured in the core region of the neutral beam (NB) injected low confinement (L-mode) plasmas on Korea superconducting tokamak advanced research. The turbulence poloidal wavenumbers are deduced from the frequencies and poloidal rotation velocities in the laboratory frame, measured by the multichannel microwave imaging reflectometer. Linear and nonlinear gyrokinetic simulations also predict the unstable modes with the normalized wavenumber kθρs∼ 0.4, consistent with the measurement. Comparison of the measured frequencies with the intrinsic mode frequencies from the linear simulations indicates that the measured ones are primarily due to the E × B flow velocity in the NB-injected fast rotating plasmas.
authors.affiliation: National Fusion Research Institute, Daejeon 34133, South Korea.
authors.forename: W
authors.initials: W
authors.lastname: Lee
authors.affiliation: Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, South Korea.
authors.forename: J
authors.initials: J
authors.lastname: Leem
authors.affiliation: Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, South Korea.
authors.forename: G S
authors.initials: GS
authors.lastname: Yun
authors.affiliation: National Fusion Research Institute, Daejeon 34133, South Korea.
authors.forename: H K
authors.initials: HK
authors.lastname: Park
authors.affiliation: National Fusion Research Institute, Daejeon 34133, South Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Ko
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA.
authors.forename: W X
authors.initials: WX
authors.lastname: Wang
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA.
authors.forename: R V
authors.initials: RV
authors.lastname: Budny
authors.affiliation: University of California at Davis, Davis, California 95616, USA.
authors.forename: N C
authors.initials: NC
authors.lastname: Luhmann
authors.affiliation: Kyungpook National University, Daegu 41566, South Korea.
authors.forename: K W
authors.initials: KW
authors.lastname: Kim