Measurement of edge plasma parameters and their electrostatic fluctuationson the HT-7 superconducting tokamak

Citation
Wh. Wang et al., Measurement of edge plasma parameters and their electrostatic fluctuationson the HT-7 superconducting tokamak, ACT PHY C E, 50(8), 2001, pp. 1521-1527
Citations number
32
Language
CHINESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
ACTA PHYSICA SINICA
ISSN journal
1000-3290 → ACNP
Volume
50
Issue
8
Year of publication
2001
Pages
1521 - 1527
Database
ISI
SICI code
1000-3290(200108)50:8<1521:MOEPPA>2.0.ZU;2-4
Abstract
The radial profiles of the electron temperature T-e, the electron density n (e), the plasma potential phi (p), the toroidal Mach number M-// and their electrostatic fluctuations in the plasma boundary region of the HT-7 superc onducting tokamak have been measured with a multiarray of Langmuir probes a nd a set of Mach probes, under the conditions of both ohmic discharge and a lower hybrid current drive. The experimental results show that, under ohmi c discharge condition I there is a poloidal velocity shear layer located in the vicinity of the limiter radius, which has a suppression effect on the fluctuations and results in the increase of the radial gradients of T-e and n(e) LHCD intensifies the shear. In the same radial position of the poloid al shear layer, there is also a radial shear with the toroidal velocity, wh ich could be the drive source of the mean poloidal flow needed by the forma tion for radial electric field.