# Perpendicular momentum input of lower hybrid waves and its influence on driving plasma rotation.

## Abstract

The mechanism of perpendicular momentum input of lower hybrid waves and its influence on plasma rotation are studied. Discussion for parallel momentum input of lower hybrid waves is presented for comparison. It is found out that both toroidal and poloidal projections of perpendicular momentum input of lower hybrid waves are stronger than those of parallel momentum input. The perpendicular momentum input of lower hybrid waves therefore plays a dominant role in forcing the changes of rotation velocity observed during lower hybrid current drive. Lower hybrid waves convert perpendicular momentum carried by the waves into the momentum of dc electromagnetic field by inducing a resonant-electron flow across flux surfaces therefore charge separation and a radial dc electric field. The dc field releases its momentum into plasma through the Lorentz force acting on the radial return current driven by the radial electric field. Plasma is spun up by the Lorentz force. An improved quasilinear theory with gyro-phase dependent distribution function is developed to calculate the radial flux of resonant electrons. Rotations are determined by a set of fluid equations for bulk electrons and ions, which are solved numerically by applying a finite-difference method. Analytical expressions for toroidal and poloidal rotations are derivedmore »

- Authors:

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

- Publication Date:

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

- Sponsoring Org.:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)

- OSTI Identifier:
- 1355669

- DOE Contract Number:
- AC02-09CH11466

- Resource Type:
- Thesis/Dissertation

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; perpendicular momentum; lower hybrid waves; plasma rotation

### Citation Formats

```
Guan, Xiaoyin.
```*Perpendicular momentum input of lower hybrid waves and its influence on driving plasma rotation.*. United States: N. p., 2017.
Web.

```
Guan, Xiaoyin.
```*Perpendicular momentum input of lower hybrid waves and its influence on driving plasma rotation.*. United States.

```
Guan, Xiaoyin. Fri .
"Perpendicular momentum input of lower hybrid waves and its influence on driving plasma rotation.". United States.
doi:.
```

```
@article{osti_1355669,
```

title = {Perpendicular momentum input of lower hybrid waves and its influence on driving plasma rotation.},

author = {Guan, Xiaoyin},

abstractNote = {The mechanism of perpendicular momentum input of lower hybrid waves and its influence on plasma rotation are studied. Discussion for parallel momentum input of lower hybrid waves is presented for comparison. It is found out that both toroidal and poloidal projections of perpendicular momentum input of lower hybrid waves are stronger than those of parallel momentum input. The perpendicular momentum input of lower hybrid waves therefore plays a dominant role in forcing the changes of rotation velocity observed during lower hybrid current drive. Lower hybrid waves convert perpendicular momentum carried by the waves into the momentum of dc electromagnetic field by inducing a resonant-electron flow across flux surfaces therefore charge separation and a radial dc electric field. The dc field releases its momentum into plasma through the Lorentz force acting on the radial return current driven by the radial electric field. Plasma is spun up by the Lorentz force. An improved quasilinear theory with gyro-phase dependent distribution function is developed to calculate the radial flux of resonant electrons. Rotations are determined by a set of fluid equations for bulk electrons and ions, which are solved numerically by applying a finite-difference method. Analytical expressions for toroidal and poloidal rotations are derived using the same hydrodynamic model.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {Fri Sep 01 00:00:00 EDT 2017},

month = {Fri Sep 01 00:00:00 EDT 2017}

}