Nonlinear evolution of the lower hybrid irregularities in artificially created dusty space plasmas

Abstract

[1] Plasma turbulence associated with the creation of an artificial dust layer in the earth's ionosphere is investigated. The lower hybrid turbulence is considered as the dust is injected across the geomagnetic field into the background plasma, which generates irregularities at times much longer than the dust charging period. A two-dimensional hybrid particle-in-cell model is developed to investigate the lower hybrid instability driven by the streaming charged dust beam. It is shown that turbulence near the lower hybrid frequency is generated which has spatial structure with enhanced electric fields in localized density depletions. The wave saturation involves ion and dust heating. Energization of ions perpendicular to the magnetic field is observed. The ratio of electron plasma frequency to electron gyro frequency plays an important role on the lower hybrid irregularity spatial structure. Important parameters of the dust cloud that impact nonlinear evolution of the waves are discussed for the regimes of upcoming space experiments. Similarities between past observations of lower hybrid turbulence observed during passive space experiments in the auroral region and lower hybrid turbulence generated by such active experiments is discussed.Citation: Fu, H., and W. A. Scales (2012), Nonlinear evolution of the lower hybrid irregularities in artificially created dusty space plasmas,

Model for charged dust expansion across a magnetic field

“…The full Poisson's equation 0 r 2 / ¼ Àðq e n e þ q i n i þ q d n d Þ was solved by spectral methods, and the electric field was obtained by E ¼ Àr/, where / is the electrostatic potential and 0 is the vacuum permittivity. 23 The dynamics of ions are modeled as discrete particles with the standard Particle-In-Cell PIC method 24 by integrating the Lorentz force equation. The particle ion density loss is…”