# Two-fluid physics and field-reversed configurations

## Abstract

In this paper, algorithms for the solution of two-fluid plasma equations are presented and applied to the study of field-reversed configurations (FRCs). The two-fluid model is more general than the often used magnetohydrodynamic (MHD) model. The model takes into account electron inertia, charge separation, and the full electromagnetic field equations, and it allows for separate electron and ion motion. The algorithm presented is the high-resolution wave propagation scheme. The wave propagation method is based on solutions to the Riemann problem at cell interfaces. Operator splitting is used to incorporate the Lorentz and electromagnetic source terms. The algorithms are benchmarked against the Geospace Environmental Modeling Reconnection Challenge problem. Equilibrium of FRC is studied. It is shown that starting from a MHD equilibrium produces a relaxed two-fluid equilibrium with strong flows at the FRC edges due to diamagnetic drift. The azimuthal electron flow causes lower-hybrid drift instabilities (LHDI), which can be captured if the ion gyroradius is well resolved. The LHDI is known to be a possible source of anomalous resistivity in many plasma configurations. LHDI simulations are performed in slab geometries and are compared to recent experimental results.

- Authors:

- Tech-X Corporation, 5621 Arapahoe Avenue - Suite A, Boulder, Colorado 80303 (United States)
- (United States)

- Publication Date:

- OSTI Identifier:
- 20975039

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 5; Other Information: DOI: 10.1063/1.2742570; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALGORITHMS; DRIFT INSTABILITY; ELECTRONS; FIELD-REVERSED THETA PINCH DEVICES; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; MAGNETOHYDRODYNAMICS; MHD EQUILIBRIUM; PLASMA; PLASMA DIAMAGNETISM; PLASMA FLUID EQUATIONS; PLASMA SIMULATION; REVERSE-FIELD PINCH; REVERSED-FIELD PINCH DEVICES

### Citation Formats

```
Hakim, A., Shumlak, U., and Aerospace and Energetics Research Program, University of Washington, Seattle, Washington 98195-2600.
```*Two-fluid physics and field-reversed configurations*. United States: N. p., 2007.
Web. doi:10.1063/1.2742570.

```
Hakim, A., Shumlak, U., & Aerospace and Energetics Research Program, University of Washington, Seattle, Washington 98195-2600.
```*Two-fluid physics and field-reversed configurations*. United States. doi:10.1063/1.2742570.

```
Hakim, A., Shumlak, U., and Aerospace and Energetics Research Program, University of Washington, Seattle, Washington 98195-2600. Tue .
"Two-fluid physics and field-reversed configurations". United States.
doi:10.1063/1.2742570.
```

```
@article{osti_20975039,
```

title = {Two-fluid physics and field-reversed configurations},

author = {Hakim, A. and Shumlak, U. and Aerospace and Energetics Research Program, University of Washington, Seattle, Washington 98195-2600},

abstractNote = {In this paper, algorithms for the solution of two-fluid plasma equations are presented and applied to the study of field-reversed configurations (FRCs). The two-fluid model is more general than the often used magnetohydrodynamic (MHD) model. The model takes into account electron inertia, charge separation, and the full electromagnetic field equations, and it allows for separate electron and ion motion. The algorithm presented is the high-resolution wave propagation scheme. The wave propagation method is based on solutions to the Riemann problem at cell interfaces. Operator splitting is used to incorporate the Lorentz and electromagnetic source terms. The algorithms are benchmarked against the Geospace Environmental Modeling Reconnection Challenge problem. Equilibrium of FRC is studied. It is shown that starting from a MHD equilibrium produces a relaxed two-fluid equilibrium with strong flows at the FRC edges due to diamagnetic drift. The azimuthal electron flow causes lower-hybrid drift instabilities (LHDI), which can be captured if the ion gyroradius is well resolved. The LHDI is known to be a possible source of anomalous resistivity in many plasma configurations. LHDI simulations are performed in slab geometries and are compared to recent experimental results.},

doi = {10.1063/1.2742570},

journal = {Physics of Plasmas},

number = 5,

volume = 14,

place = {United States},

year = {Tue May 15 00:00:00 EDT 2007},

month = {Tue May 15 00:00:00 EDT 2007}

}