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

Wang, WH Yu, CX Xu, YH Wen, YZ Ling, BL Mei, S Wan, BN

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

32

CHINESE

Article

Physics

ACTA PHYSICA SINICA

1000-3290 → ACNP

50

8

2001

1521 - 1527

ISI

1000-3290(200108)50:8<1521:MOEPPA>2.0.ZU;2-4

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.