Lower Hybrid Turbulence Associated With Creation of Dusty Plasmas in the Near-Earth Space Environment

摘要

Plasma turbulence associated with the creation of an artificial dust layer in the Earth's ionosphere is investigated. Two scenarios are considered for plasma irregularity generation as dust is injected at an oblique angle across the magnetic field. The first is a shear-driven plasma instability due to inhomogeneities in the boundary layer between the injected charged dust layer and the background plasma. This begins to appear at very early times relative to the release of the dust into the plasma, which is on the order of or less than the dust charging time period. The second mechanism is free streaming of the dust relative to the background plasma, which produces irregularities at times much longer than the dust charging period and also longer than the dust plasma period. Although both mechanisms are shown to produce turbulence in the lower hybrid frequency range, the resulting irregularities have important differences in their physical characteristics. A comparison between the processes is made to determine the consequences for upcoming observations. Both processes are shown to have the possibility to generate turbulence after the release of dust for the regimes of upcoming space experiments over a range of timescales.