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arXiv physics/0411116physics.plasm-ph
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磁化尘埃等离子体放电:正负空间电荷模式

The magnetized dusty plasma discharge : negative and positive space charge modes

Neil F. Cramer, Sergey Vladimirov

摘要:

本文分析了尘埃等离子体中跨越磁场的放电结构。尘埃大颗粒带负电,但由于质量大而未被磁化。电子是高度磁化的,离子具有中等磁化强度。这导致不同物质在磁场上的不同传输速率。根据磁场的大小和不同物质上的相对电荷,尘埃颗粒可能是主要的电流载体。然后,电极附近的空间电荷云将由不同物质的相对迁移率确定。放电可以以两种模式中的一种模式操作,即以强阴极下降为特征的正空间电荷(PSC)模式和以宽阳极下降为特征的负空间电荷(NSC)模式。尘埃粒子特有的特征也可以在放电结构中发挥作用,例如颗粒上的可变平衡电荷,取决于局部电位和物种温度,重力对颗粒动力学的影响,以及颗粒的充电速率。尘埃颗粒也可以形成一种有序的结构,即尘埃等离子体晶体。不同种类的流体模型被用来计算所产生的放电的结构,将上述效果。从PSC模式的过渡到NSC模式的磁场,压力和灰尘的性质是不同的。

英文摘要:

The structure of a discharge across a magnetic field in a dusty plasma is analysed. The dust macroparticles are negatively charged, but are unmagnetized because of their high mass. The electrons are highly magnetized, and the ions have intermediate magnetization. This results in different transport rates of the different species across the magnetic field. Depending on the size of the magnetic field, and the relative charge on the different species, the dust grains can be the dominant current carrier. The space charge clouds near the electrodes will then be determined by the relative mobility of the different species. The discharge can operate in one of two modes, a positive space charge (PSC) mode, characterized by a strong cathode fall, and a negative space charge (NSC) mode, characterized by a broad anode fall. Features unique to the dust particles can also play a role in the structure of the discharge, such as the variable equilibrium charge on the grains, dependent on the local potential and species temperatures, the effect of gravity on the grain dynamics, and the rate of charging of the grains. The dust grains can also form an ordered structure, the dust-plasma crystal. A fluid model of the different species is used to calculate the structure of the resulting discharge, incorporating the above effects. The transition from the PSC mode to the NSC mode as the magnetic field, pressure and dust properties are varied is demonstrated.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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