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Title: Structure of Langmuir and electromagnetic collapsing wave packets in two-dimensional strong plasma turbulence

Abstract

Nucleating and collapsing wave packets relevant to electromagnetic strong plasma turbulence are studied theoretically in two dimensions. Model collapsing Langmuir and transverse potentials are constructed as superpositions of approximate eigenstates of a spherically symmetric density well. Electrostatic and electromagnetic potentials containing only components with azimuthal quantum numbers m=0, 1, 2 are found to give a good representation of the electric fields of nucleating collapsing wave packets in turbulence simulations. The length scales of these trapped states are related to the electron thermal speed v{sub e} and the length scale of the density well. It is shown analytically that the electromagnetic trapped states change with v{sub e} and that for v{sub e} < or approx. 0.17c they are delocalized, in accord with recent simulations. In this case, the Langmuir mode collapses independently, as in electrostatic plasma turbulence. For v{sub e} > or approx. 0.17c, the Langmuir and transverse modes remain coupled during collapse, with autocorrelation lengths in a constant ratio. An investigation of energy transfer to packets localized in density wells shows that the strongest power transfer to the nucleating state occurs for Langmuir waves. Energy transitions between different trapped and free states for collapsing wave packets are studied, and themore » transition rate from trapped Langmuir to free plane electromagnetic waves is calculated and related to the emission of electromagnetic waves at the plasma frequency.« less

Authors:
; ; ; ;  [1]
  1. School of Physics, University of Sydney, NSW 2006, Sydney (Australia) and Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
20975151
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 14; Journal Issue: 7; Other Information: DOI: 10.1063/1.2749495; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; EIGENSTATES; ELECTRIC FIELDS; ELECTROMAGNETIC RADIATION; ELECTRONS; EMISSION; ENERGY TRANSFER; LANGMUIR FREQUENCY; PLASMA; PLASMA DENSITY; PLASMA SIMULATION; PLASMA WAVES; POTENTIALS; QUANTUM NUMBERS; TRAPPING; TURBULENCE; TWO-DIMENSIONAL CALCULATIONS; WAVE PACKETS

Citation Formats

Alinejad, H, Robinson, P A, Cairns, I H, Skjaeraasen, O, Sobhanian, S, School of Physics, University of Sydney, NSW 2006, Sydney, School of Physics, University of Sydney, NSW 2006, Sydney, Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0314 Oslo, and Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo, and Faculty of Physics, Tabriz University, Tabriz 51664. Structure of Langmuir and electromagnetic collapsing wave packets in two-dimensional strong plasma turbulence. United States: N. p., 2007. Web. doi:10.1063/1.2749495.
Alinejad, H, Robinson, P A, Cairns, I H, Skjaeraasen, O, Sobhanian, S, School of Physics, University of Sydney, NSW 2006, Sydney, School of Physics, University of Sydney, NSW 2006, Sydney, Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0314 Oslo, and Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo, & Faculty of Physics, Tabriz University, Tabriz 51664. Structure of Langmuir and electromagnetic collapsing wave packets in two-dimensional strong plasma turbulence. United States. doi:10.1063/1.2749495.
Alinejad, H, Robinson, P A, Cairns, I H, Skjaeraasen, O, Sobhanian, S, School of Physics, University of Sydney, NSW 2006, Sydney, School of Physics, University of Sydney, NSW 2006, Sydney, Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0314 Oslo, and Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo, and Faculty of Physics, Tabriz University, Tabriz 51664. Sun . "Structure of Langmuir and electromagnetic collapsing wave packets in two-dimensional strong plasma turbulence". United States. doi:10.1063/1.2749495.
@article{osti_20975151,
title = {Structure of Langmuir and electromagnetic collapsing wave packets in two-dimensional strong plasma turbulence},
author = {Alinejad, H and Robinson, P A and Cairns, I H and Skjaeraasen, O and Sobhanian, S and School of Physics, University of Sydney, NSW 2006, Sydney and School of Physics, University of Sydney, NSW 2006, Sydney and Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0314 Oslo and and Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo and Faculty of Physics, Tabriz University, Tabriz 51664},
abstractNote = {Nucleating and collapsing wave packets relevant to electromagnetic strong plasma turbulence are studied theoretically in two dimensions. Model collapsing Langmuir and transverse potentials are constructed as superpositions of approximate eigenstates of a spherically symmetric density well. Electrostatic and electromagnetic potentials containing only components with azimuthal quantum numbers m=0, 1, 2 are found to give a good representation of the electric fields of nucleating collapsing wave packets in turbulence simulations. The length scales of these trapped states are related to the electron thermal speed v{sub e} and the length scale of the density well. It is shown analytically that the electromagnetic trapped states change with v{sub e} and that for v{sub e} < or approx. 0.17c they are delocalized, in accord with recent simulations. In this case, the Langmuir mode collapses independently, as in electrostatic plasma turbulence. For v{sub e} > or approx. 0.17c, the Langmuir and transverse modes remain coupled during collapse, with autocorrelation lengths in a constant ratio. An investigation of energy transfer to packets localized in density wells shows that the strongest power transfer to the nucleating state occurs for Langmuir waves. Energy transitions between different trapped and free states for collapsing wave packets are studied, and the transition rate from trapped Langmuir to free plane electromagnetic waves is calculated and related to the emission of electromagnetic waves at the plasma frequency.},
doi = {10.1063/1.2749495},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 7,
volume = 14,
place = {United States},
year = {2007},
month = {7}
}