# On the Toroidal Plasma Rotations Induced by Lower Hybrid Waves

## Abstract

A theoretical model is developed to explain the plasma rotations induced by lower hybrid waves in Alcator C-Mod. In this model, torodial rotations are driven by the Lorentz force on the bulk electron flow across flux surfaces, which is a response of the plasma to the resonant-electron flow across flux surfaces induced by the lower hybrid waves. The flow across flux surfaces of the resonant electrons and the bulk electrons are coupled through the radial electric fi eld initiated by the resonant electrons, and the friction between ions and electrons transfers the toroidal momentum to ions from electrons. An improved quasilinear theory with gyrophase dependent distribution function is developed to calculate the perpendicular resonant-electron flow. Toroidal rotations are determined using a set of fluid equations for bulk electrons and ions, which are solved numerically by a fi nite- difference method. Numerical results agree well with the experimental observations in terms of flow pro file and amplitude. The model explains the strong correlation between torodial flow and internal inductance observed experimentally, and predicts both counter-current and co-current flows, depending on the perpendicular wave vectors of the lower hybrid waves. __________________________________________________

- Authors:

- Publication Date:

- Research Org.:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC)

- OSTI Identifier:
- 1056357

- Report Number(s):
- PPPL-4831

- DOE Contract Number:
- DE-ACO2-09CH11466

- Resource Type:
- Technical Report

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Lower Hybrid Waves, Transport Theory

### Citation Formats

```
Guan, Xiaoyin, Qin, Hong, Liu, Jian, and Fisch, Nathaniel J.
```*On the Toroidal Plasma Rotations Induced by Lower Hybrid Waves*. United States: N. p., 2012.
Web. doi:10.2172/1056357.

```
Guan, Xiaoyin, Qin, Hong, Liu, Jian, & Fisch, Nathaniel J.
```*On the Toroidal Plasma Rotations Induced by Lower Hybrid Waves*. United States. doi:10.2172/1056357.

```
Guan, Xiaoyin, Qin, Hong, Liu, Jian, and Fisch, Nathaniel J. Wed .
"On the Toroidal Plasma Rotations Induced by Lower Hybrid Waves". United States. doi:10.2172/1056357. https://www.osti.gov/servlets/purl/1056357.
```

```
@article{osti_1056357,
```

title = {On the Toroidal Plasma Rotations Induced by Lower Hybrid Waves},

author = {Guan, Xiaoyin and Qin, Hong and Liu, Jian and Fisch, Nathaniel J.},

abstractNote = {A theoretical model is developed to explain the plasma rotations induced by lower hybrid waves in Alcator C-Mod. In this model, torodial rotations are driven by the Lorentz force on the bulk electron flow across flux surfaces, which is a response of the plasma to the resonant-electron flow across flux surfaces induced by the lower hybrid waves. The flow across flux surfaces of the resonant electrons and the bulk electrons are coupled through the radial electric fi eld initiated by the resonant electrons, and the friction between ions and electrons transfers the toroidal momentum to ions from electrons. An improved quasilinear theory with gyrophase dependent distribution function is developed to calculate the perpendicular resonant-electron flow. Toroidal rotations are determined using a set of fluid equations for bulk electrons and ions, which are solved numerically by a fi nite- difference method. Numerical results agree well with the experimental observations in terms of flow pro file and amplitude. The model explains the strong correlation between torodial flow and internal inductance observed experimentally, and predicts both counter-current and co-current flows, depending on the perpendicular wave vectors of the lower hybrid waves. __________________________________________________},

doi = {10.2172/1056357},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2012},

month = {11}

}