Caviton dynamics in strong Langmuir turbulence

Conference · Sun Jan 01 04:00:00 EST 1989

DOI:https://doi.org/10.1088/0031-8949/1990/T30/020· OSTI ID:6067377

DuBois, D; Rose, H A; Russell, D

Recent studies based on long time computer simulations of Langmuir turbulence as described by Zakharov's model will be reviewed. These show that for strong to moderate ion sound samping the turbulent energy is dominantly in nonlinear ''caviton'' excitations which are localized in space and time. A local caviton model will be presented which accounts for the nucleation-collapse-burnout cycles of individual cavitons as well as their space-time correlations. This model is in detailed agreement with many features of the electron density fluctuation spectra in the ionosphere modified by powerful hf waves as measured by incoherent scatter radar. Recently such observations have verified a prediction of the theory that ''free'' Langmuir waves are emitted in the caviton collapse process. These observations and theoretical considerations also strongly imply that cavitons in the heated ionosphere, under certain conditions, evolve to states in which they are ordered in space and time. The sensitivity of the high frequency Langmuir field dynamics to the low frequency ion density fluctuations and the related caviton nucleation process will be discussed. 40 refs., 19 figs.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6067377
• Report Number(s): LA-UR-89-1848; CONF-8905156-1; ON: DE89012635
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CAVITATION
COMPUTERIZED SIMULATION
DAMPING
DYNAMICS
EARTH ATMOSPHERE
ELECTRIC FIELDS
ENERGY SPECTRA
IONOSPHERE
LANDAU DAMPING
MECHANICS
PLANETARY IONOSPHERES
PLASMA WAVES
SIMULATION
SOUND WAVES
SPACE-TIME
SPECTRA
TURBULENCE