Vlasov simulation of modulational instability and Langmuir collapse

Journal Article · Sat Apr 01 04:00:00 EST 1995 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.871391· OSTI ID:6448757

Wang, J G; Payne, G L ^[1]; DuBois, D F; Rose, H A ^[2]

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1. Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242 (United States)
2. T-DOT, MS B262, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Vlasov simulations are developed to study the one-dimensional modulational instability and Langmuir collapse in a plasma driven by an external field. Both electrons and ions in the plasma are described by the Vlasov equations. The external driving field energy density is [similar to]10[sup [minus]3] times the initial electron thermal energy density. The plasma has a mass ratio of [ital m][sub [ital i]]/[ital m][sub [ital e]]=1836, and a temperature ratio of [ital T][sub [ital i]]/[ital T][sub [ital e]]=0.1 or 1.0, where [ital m][sub [ital i]], [ital m][sub [ital e]], [ital T][sub [ital i]], and [ital T][sub [ital e]] are the ion mass, electron mass, ion temperature, and electron temperature. The modulational instability is saturated by the formation of Langmuir cavitons which later collapse and burn out due to the strong wave--particle interactions. The particle heating during a single Langmuir collapse is small under this weak driving field. The accelerated electron and ion jet-like streams in phase space as well as the nucleation of cavitons are observed during the evolution. Zakharov equations with the same parameters and similar initial conditions are also simulated, and the results are compared with those of the Vlasov simulations. The two models agree with each other quantitatively up to the first collapse following the saturation of exponential growth; dynamic differences appear after the first collapse.

• OSTI ID: 6448757
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 2:4; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700330 -- Plasma Kinetics
Transport
& Impurities-- (1992-)
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
BOLTZMANN-VLASOV EQUATION
COLLISIONLESS PLASMA
DIFFERENTIAL EQUATIONS
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
EQUATIONS
F REGION
HEATING
HIGH-FREQUENCY HEATING
IONOSPHERE
PARTIAL DIFFERENTIAL EQUATIONS
PLANETARY IONOSPHERES
PLASMA
PLASMA HEATING
PLASMA SIMULATION
PLASMA WAVES
RADIATIONS
RADIOWAVE RADIATION
SIMULATION
TURBULENCE