# Symmetries of a reduced fluid-gyrokinetic system

## Abstract

Symmetries of a fluid-gyrokinetic model are investigated using Lie group techniques. Specifically the nonlinear system constructed by Zocco and Schekochihin (Zocco & Schekochihin 2011), which combines nonlinear fluid equations with a drift-kinetic description of parallel electron dynamics, is studied. Significantly, this model is fully gyrokinetic, allowing for arbitrary $$k_{\bot \rho I}$$ where $$k_\bot$$ is the perpendicular wave vector of the fluctuations and $$\rho I}$$ is the ion gyroradius. The model includes integral operators corresponding to gyroaveraging as well as the moment equations relating fluid variables to the kinetic distribution function. A large variety of exact symmetries is uncovered, some of which have unexpected form. Using these results, new nonlinear solutions are constructed, including a helical generalization of the Chapman-Kendall solution for a collapsing current sheet.

- Authors:

- Publication Date:

- DOE Contract Number:
- FG02-91ER54109; FG02-04ER54742; SC0014664

- Research Org.:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Univ. of Texas, Austin, TX (United States)

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

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

- OSTI Identifier:
- 1880273

- DOI:
- https://doi.org/10.7910/DVN/9HF5L0

### Citation Formats

```
White, R. L., Hazeltine, R. D., and Loureiro, N. F.
```*Symmetries of a reduced fluid-gyrokinetic system*. United States: N. p., 2018.
Web. doi:10.7910/DVN/9HF5L0.

```
White, R. L., Hazeltine, R. D., & Loureiro, N. F.
```*Symmetries of a reduced fluid-gyrokinetic system*. United States. doi:https://doi.org/10.7910/DVN/9HF5L0

```
White, R. L., Hazeltine, R. D., and Loureiro, N. F. 2018.
"Symmetries of a reduced fluid-gyrokinetic system". United States. doi:https://doi.org/10.7910/DVN/9HF5L0. https://www.osti.gov/servlets/purl/1880273. Pub date:Thu Nov 01 00:00:00 EDT 2018
```

```
@article{osti_1880273,
```

title = {Symmetries of a reduced fluid-gyrokinetic system},

author = {White, R. L. and Hazeltine, R. D. and Loureiro, N. F.},

abstractNote = {Symmetries of a fluid-gyrokinetic model are investigated using Lie group techniques. Specifically the nonlinear system constructed by Zocco and Schekochihin (Zocco & Schekochihin 2011), which combines nonlinear fluid equations with a drift-kinetic description of parallel electron dynamics, is studied. Significantly, this model is fully gyrokinetic, allowing for arbitrary $k_{\bot \rho I}$ where $k_\bot$ is the perpendicular wave vector of the fluctuations and $\rho I}$ is the ion gyroradius. The model includes integral operators corresponding to gyroaveraging as well as the moment equations relating fluid variables to the kinetic distribution function. A large variety of exact symmetries is uncovered, some of which have unexpected form. Using these results, new nonlinear solutions are constructed, including a helical generalization of the Chapman-Kendall solution for a collapsing current sheet.},

doi = {10.7910/DVN/9HF5L0},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2018},

month = {11}

}

Works referencing / citing this record:

##
Symmetries of a reduced fluid-gyrokinetic system

journal, March 2018

- White, R. L.; Hazeltine, R. D.; Loureiro, N. F.
- Journal of Plasma Physics, Vol. 84, Issue 2