Electrostatic Fluctuations Measured in Low Temperature Helical Plasmas with Low Collisionality

Masaki Takeuchi (1) , Ryosuke Ikeda (1) , Takafumi Ito (1) , Kazuo Toi (2) , Chihiro Suzuki (2) , Go Matsunaga (3) , Chs Group (2)

1 Department of Energy Engineering and Science [Nagoya]
2 NIFS - National Institute for Fusion Science
3 Japan Atomic Energy Research Institute

Electrostatic fluctuations have been measured by Langmuir probes from edge to core plasma region in low temperature helical plasmas which are produced by 2.45 GHz microwaves at very low field less than 0.1T. The principal dimensionless parameters of the plasmas, that is, the normalized electron-ion collision frequency νei*, and averaged plasma beta βφ and others are in the same range of them in high temperature plasmas, except the normalized gyro radius ρs*. The data on fluctuation characteristics from the dimensionally similar low temperature plasmas may give an important insight into understanding of turbulent transport in high temperature plasmas. Dependences of fluctuation amplitudes on the radial electric field shear, ρs* and νei* are investigated. Electrostatic fluctuations propagate in electron-diamagnetic drift direction have been observed in the plasma edge region and in ion-diamagnetic drift direction in the plasma core region.

Mots clés: turbulent transport; dimensionally similar plasma; electrostatic fluctuation; Langmuir probe

Domaines: Physique des plasmas [physics.plasm-ph]

Masaki Takeuchi, Ryosuke Ikeda, Takafumi Ito, Kazuo Toi, Chihiro Suzuki, et al.. Electrostatic Fluctuations Measured in Low Temperature Helical Plasmas with Low Collisionality. 2004. ⟨hal-00002011⟩