Turbulence in edge and core transport barriers: new experimental results and modeling

Abstract

In this paper, recent progressive studies on experimental analysis and theoretical models for turbulence phenomena around the transport barriers in high-performance magnetic confined fusion plasma are reviewed. The linkage of radial electric fields and turbulence, the importance of radial electric field curvature, and observations of spatiotemporal turbulence structures are described with related theoretical models.

Spatio-temporal dynamics of turbulence trapped in geodesic acoustic modes

“…2 The experimental validation for the interaction between sheared flows and turbulence has been reported. [3][4][5][6][7] The spatial structure of the energy transfer functions between the turbulence and the zonal flows (ZFs) has been observed in a basic plasma experiment. 8 In researches on the interaction between ZFs and turbulence, the predator-prey model has been widely studied [9][10][11][12][13] and applied to experiments.…”

Development and application of radar reflectometer using micro to infrared waves

“…The dynamic behaviors of density/magnetic fluctuations during the L to H transition [27,28], the fluctuation spectra of edge localized modes (ELMs) [20,29], and fluctuations over the whole plasma radius from the scrape-off layer (SOL) to the core have been measured using various types of reflectometry [25,30].…”

Microwave frequency comb Doppler reflectometer applying fast digital data acquisition system in LHD

“…For this aim, higher spatial and temporal resolution diagnostics have been developed and applied in several devices. 1 Microwave Doppler reflectometry (also called Doppler back-scattering: DBS) has the capability to measure the perpendicular velocity v ⊥ of electron density fluctuations, the radial electric field E r , and the perpendicular wavenumber spectrum S(k ⊥ ) in magnetized confinement plasmas, using its unique advantage, that is, the combination with the back-scattering method (which provides a wavenumber resolution) and reflectometry (which provides a high-spatial resolution). 2 As a result, a number of systems have been used in worldwide fusion plasma devices, such as tokamaks (Tuman-3M, 3 ASDEX Upgrade, 4,6,7 Tore Supra, 8,9 DIII-D, 10 JT-60U, 11 MAST, 12 and JET 13 ) and helical/stellarators (Wendelstein 7-AS, 2,14 TJ-II, 15 and LHD 16,17 ).…”