Electrostatic fluctuations and turbulent, transport studies in the HT-7 superconducting tokamak edge plasmas

Citation
Wh. Wang et al., Electrostatic fluctuations and turbulent, transport studies in the HT-7 superconducting tokamak edge plasmas, ACT PHY C E, 50(10), 2001, pp. 1956-1963
Citations number
27
Language
CHINESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
ACTA PHYSICA SINICA
ISSN journal
1000-3290 → ACNP
Volume
50
Issue
10
Year of publication
2001
Pages
1956 - 1963
Database
ISI
SICI code
1000-3290(200110)50:10<1956:EFATTS>2.0.ZU;2-X
Abstract
Electrostatic fluctuations and turbulence-induced particle flux have been i nvestigated in the plasma boundary region of the HT-7 superconducting tokam ak. There is a poloidal velocity shear layer driven by E-r x B-T located in the vicinity of the limiter radius, which has a suppression effect on the fluctuations and results in reductions in the normalized fluctuation level, coherence between the two plasma parameter fluctuations of <(<phi>)over ti lde>(p) (T) over tilde (e) and (n) over tilde (e). The radial decorrelation effect of the poloidal velocity shear causes a decrease in the turbulent f lux. The time evolution of the turbulent flux shows bursts in turbulent tra nsport. The frequency range where the turbulent flux, which comes in bursts , is dominant has been identified. It is in this frequency range that the s pectral region with power decay close to 1/f of the power spectrum of the f loating voltage fluctuation has been found. This result could be a signatur e of the turbulent transport close to instability threholds.