ISSN:
1089-7674
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Beam-driven Langmuir turbulence is studied in two moderately magnetized (Ωe≈ωe) space-plasma regimes: regions of the lower solar corona and the Earth's auroral ionosphere. The turbulence is modeled using modified Zakharov equations, which are employed in two-dimensional numerical simulations. For coronal parameters, highly anisotropic coherent wave packets form and collapse when Ωe〈ωe. By contrast, the turbulence is phase incoherent when Ωe(approximately-greater-than)ωe, as a result of change in the topology of the Langmuir dispersion relation. In the auroral ionosphere, intense Langmuir waves (up to 500 mV/m) have been measured, in conjunction with field-aligned electron streams and nonthermal electron tails. Approximate agreement with high-time-resolution electric-field measurements, is found in the simulations. However, because of strong damping on nonthermal electrons, wave collapse is inhibited, irrespective of the ordering of Ωe and ωe.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.870672
Permalink