Denysenko I, Yu M Y, Stenflo L, Xu S
Theoretical Physics I, Ruhr University, D-44780 Bochum, Germany. deny@
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Jul;72(1 Pt 2):016405. doi: 10.1103/PhysRevE.72.016405. Epub 2005 Jul 28.
The electric as well as the positive- and negative-ion drag forces on an isolated dust grain in an electronegative plasma are studied for large negative-ion densities, when the negative ions are not Boltzmann distributed. The investigation is carried out for submicrometer dust particles, so that the theory of Coulomb scattering is applicable for describing ion-dust interaction. Among the forces acting on the dust grain, the negative-ion drag force is found to be important. The effects of the negative-ion density, neutral-gas pressure, and dust-grain size on the forces are also considered. It is shown that by increasing the density of the negative ions one can effectively manipulate the dust grains. Our results imply that both dust voids and balls can be formed.
研究了在大负离子密度下，当负离子不呈玻尔兹曼分布时，电负性等离子体中孤立尘埃颗粒上的电场力以及正离子和负离子拖曳力。研究针对亚微米级尘埃颗粒进行，以便库仑散射理论适用于描述离子与尘埃的相互作用。在作用于尘埃颗粒的力中，负离子拖曳力被发现很重要。还考虑了负离子密度、中性气体压力和尘埃颗粒尺寸对这些力的影响。结果表明，通过增加负离子密度可以有效地操控尘埃颗粒。我们的结果意味着可以形成尘埃空洞和尘埃球。
