Computation of the effect of neutral collisions on ion current to a floating sphere in a stationary plasma
Computation of the effect of neutral collisions on ion current to a floating sphere in a stationary plasma
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DOI：
10.1063/1.2431584
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发表时间：
2007-01-01
影响因子：
2.2
通讯作者：
Patacchini, L.
中科院分区：
文献类型：
--
作者：
Hutchinson, I. H.;Patacchini, L.
特殊坐标静电粒子和热分子在细胞（SCEPTIC）程序[I]。H.哈钦森，Plasma Physics and Controlled Fusion 45，1447（2003）]被用于计算在静止等离子体中到浮球的离子通量，包括与中性粒子的电荷交换碰撞的影响。在很低和很高的碰撞度下，计算结果与已有的计算结果吻合得很好，从而验证了程序和已有的计算结果。此外，SCEPTIC提供了定量的结果，在中间碰撞，没有分析理论。合理的协议浮动电位发现有一些以前的数值结果。对于远大于球体半径的拉姆达（De），离子收集在轨道运动限制值以上增强高达5倍，足以略微超过径向运动值，但仅在有限的碰撞性范围内。一个明确的分析适合SCEPTIC的结果提供了在整个范围内的碰撞容易评估。(c)2007年，美国物理学会。
The Specialized-Coordinate Electrostatic Particle and Thermals in Cell (SCEPTIC) code [I. H. Hutchinson, Plasma Physics and Controlled Fusion 45, 1447 (2003)] is used to compute the ion flux to a floating sphere in a stationary plasma, including the effects of charge-exchange collisions with neutrals. The results agree well with the available prior calculations at very low and very high collisionality thus validating the code and those prior calculations. In addition, SCEPTIC provides quantitative results at intermediate collisionalities where no analytic theory is available. Reasonable agreement in the floating potential is found there with some prior numerical results. For lambda(De) much greater than the sphere radius, enhancements of the ion collection above the orbital motion limited value by factors as high as 5 occur, enough to exceed slightly the radial motion value, but only over a restricted range of collisionality. An explicit analytic fit to SCEPTIC's results is provided for easy evaluation over the entire range of collisionality. (c) 2007 American Institute of Physics.