# Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality

## Abstract

The dynamics of electron-plasma waves are described at arbitrary collisionality by considering the full Coulomb collision operator. The description is based on a Hermite- Laguerre decomposition of the velocity dependence of the electron distribution function. The damping rate, frequency, and eigenmode spectrum of electron-plasma waves are found as functions of the collision frequency and wavelength. A comparison is made between the collisionless Landau damping limit, the Lenard-Bernstein and Dougherty collision operators, and the electron-ion collision operator, finding large deviations in the damping rates and eigenmode spectra. A purely damped entropy mode, characteristic of a plasma where pitch-angle scattering effects are dominant with respect to collisionless effects, is shown to emerge numerically, and its dispersion relation is analytically derived. It is shown that such a mode is absent when simplified collision operators are used, and that like-particle collisions strongly influence the damping rate of the entropy mode.

- Authors:

- Publication Date:

- DOE Contract Number:
- FG02-91ER54109

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

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

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

- OSTI Identifier:
- 1880321

- DOI:
- https://doi.org/10.7910/DVN/LOAT9C

### Citation Formats

```
Jorge, R., Ricci, P., Brunner, S., Gamba, S., Konovets, V., Loureiro, N. F., Perrone, L. M., and Teixeira, N.
```*Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality*. United States: N. p., 2018.
Web. doi:10.7910/DVN/LOAT9C.

```
Jorge, R., Ricci, P., Brunner, S., Gamba, S., Konovets, V., Loureiro, N. F., Perrone, L. M., & Teixeira, N.
```*Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality*. United States. doi:https://doi.org/10.7910/DVN/LOAT9C

```
Jorge, R., Ricci, P., Brunner, S., Gamba, S., Konovets, V., Loureiro, N. F., Perrone, L. M., and Teixeira, N. 2018.
"Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality". United States. doi:https://doi.org/10.7910/DVN/LOAT9C. https://www.osti.gov/servlets/purl/1880321. Pub date:Tue Dec 04 00:00:00 EST 2018
```

```
@article{osti_1880321,
```

title = {Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality},

author = {Jorge, R. and Ricci, P. and Brunner, S. and Gamba, S. and Konovets, V. and Loureiro, N. F. and Perrone, L. M. and Teixeira, N.},

abstractNote = {The dynamics of electron-plasma waves are described at arbitrary collisionality by considering the full Coulomb collision operator. The description is based on a Hermite- Laguerre decomposition of the velocity dependence of the electron distribution function. The damping rate, frequency, and eigenmode spectrum of electron-plasma waves are found as functions of the collision frequency and wavelength. A comparison is made between the collisionless Landau damping limit, the Lenard-Bernstein and Dougherty collision operators, and the electron-ion collision operator, finding large deviations in the damping rates and eigenmode spectra. A purely damped entropy mode, characteristic of a plasma where pitch-angle scattering effects are dominant with respect to collisionless effects, is shown to emerge numerically, and its dispersion relation is analytically derived. It is shown that such a mode is absent when simplified collision operators are used, and that like-particle collisions strongly influence the damping rate of the entropy mode.},

doi = {10.7910/DVN/LOAT9C},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2018},

month = {12}

}

Works referencing / citing this record:

##
Linear theory of electron-plasma waves at arbitrary collisionality

journal, April 2019

- Jorge, R.; Ricci, P.; Brunner, S.
- Journal of Plasma Physics, Vol. 85, Issue 2