Losseva T V, Popel S I, Yu M Y, Ma J X
Institute for Dynamics of Geospheres, Russian Academy of Sciences, Moscow 119334, Russia.
Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Apr;75(4 Pt 2):046403. doi: 10.1103/PhysRevE.75.046403. Epub 2007 Apr 24.
A self-consistent model of the ambipolar diffusion of electrons and ions in complex (dusty) plasmas accounting for the local electric fields, the dust grain charging process, and the interaction of the plasma particles with the dust grains and neutrals is presented. The dependence of the diffusion coefficient on the interaction of the electrons and ions with the dust grains as well as with the neutrals are investigated. It is shown that increase of the dust density leads to a reduction of the diffusion scale length, and this effect is enhanced at higher electron densities. The dependence of the diffusion scale length on the neutral gas pressure is found to be given by a power law, where the absolute value of the power exponent decreases with increase of the dust density. The electric field gradient and its effects are shown to be significant and should thus be taken into account in studies of complex plasmas with not very small dust densities. The possibility of observing localized coherent dissipative nonlinear dust ion-acoustic structures in an asymmetrically discharged double plasma is discussed.
本文提出了一个自洽模型，用于描述复杂（尘埃）等离子体中电子和离子的双极扩散，该模型考虑了局部电场、尘埃颗粒充电过程以及等离子体粒子与尘埃颗粒和中性粒子的相互作用。研究了扩散系数对电子和离子与尘埃颗粒以及与中性粒子相互作用的依赖性。结果表明，尘埃密度的增加会导致扩散尺度长度减小，并且在较高电子密度下这种效应会增强。发现扩散尺度长度对中性气体压力的依赖性由幂律给出，其中幂指数的绝对值随尘埃密度的增加而减小。电场梯度及其效应被证明是显著的，因此在研究尘埃密度不是非常小的复杂等离子体时应予以考虑。讨论了在非对称放电双等离子体中观测局部相干耗散非线性尘埃离子声结构的可能性。
