U.S. Department of EnergyOffice of Scientific and Technical Information
Kinetic-magnetohydrodynamic description of longitudinal sound waves in a collisionless, quasineutral plasma
Abstract
The time evolution of slow sound waves in a homogeneous, collisionless and quasineutral plasma, in particular their Landau damping, is investigated using the kinetic magnetohydrodynamics formulation of J.J. Ramos (J . Plasma Phys. vol. 81, 2015 p. 905810325; vol. 82, 2016 p. 905820607). In this approach, the electric field is eliminated from a closed, hybrid fluid-kinetic system that ensures automatically the fulfillment of the charge neutrality condition. Considering the time dependence of a spatial-Fourier-mode linear perturbation with wavevector parallel to the equilibrium magnetic field, this can be cast as a second-order self-adjoint problem with a continuum spectrum of real and positive squared frequencies. Therefore, a conventional resolution of the identity with a continuum basis of singular normal modes is guaranteed, which simplifies significantly a Van Kampen-like treatment of the Landau damping. The explicit form of such singular normal modes is obtained, along with their orthogonality relations. These are used to derive the damped time evolution of the fluid moments of solutions of initial-value problems, for the most general kinds of initial conditions. The non-zero parallel electric field is not used explicitly in this analysis, but it is calculated from any given solution after the later has been obtained.
- Authors:
-
- OSTI
- 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:
- 1880258
- DOI:
- https://doi.org/10.7910/DVN/2Q5YUA
Citation Formats
Ramos, J. J. Kinetic-magnetohydrodynamic description of longitudinal sound waves in a collisionless, quasineutral plasma. United States: N. p., 2018.
Web. doi:10.7910/DVN/2Q5YUA.
Ramos, J. J. Kinetic-magnetohydrodynamic description of longitudinal sound waves in a collisionless, quasineutral plasma. United States. doi:https://doi.org/10.7910/DVN/2Q5YUA
Ramos, J. J. 2018.
"Kinetic-magnetohydrodynamic description of longitudinal sound waves in a collisionless, quasineutral plasma". United States. doi:https://doi.org/10.7910/DVN/2Q5YUA. https://www.osti.gov/servlets/purl/1880258. Pub date:Thu Oct 25 04:00:00 UTC 2018
@article{osti_1880258,
title = {Kinetic-magnetohydrodynamic description of longitudinal sound waves in a collisionless, quasineutral plasma},
author = {Ramos, J. J.},
abstractNote = {The time evolution of slow sound waves in a homogeneous, collisionless and quasineutral plasma, in particular their Landau damping, is investigated using the kinetic magnetohydrodynamics formulation of J.J. Ramos (J . Plasma Phys. vol. 81, 2015 p. 905810325; vol. 82, 2016 p. 905820607). In this approach, the electric field is eliminated from a closed, hybrid fluid-kinetic system that ensures automatically the fulfillment of the charge neutrality condition. Considering the time dependence of a spatial-Fourier-mode linear perturbation with wavevector parallel to the equilibrium magnetic field, this can be cast as a second-order self-adjoint problem with a continuum spectrum of real and positive squared frequencies. Therefore, a conventional resolution of the identity with a continuum basis of singular normal modes is guaranteed, which simplifies significantly a Van Kampen-like treatment of the Landau damping. The explicit form of such singular normal modes is obtained, along with their orthogonality relations. These are used to derive the damped time evolution of the fluid moments of solutions of initial-value problems, for the most general kinds of initial conditions. The non-zero parallel electric field is not used explicitly in this analysis, but it is calculated from any given solution after the later has been obtained.},
doi = {10.7910/DVN/2Q5YUA},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Oct 25 04:00:00 UTC 2018},
month = {Thu Oct 25 04:00:00 UTC 2018}
}