Ion collection by cylindrical probes in weakly collisional plasmas
Ion collection by cylindrical probes in weakly collisional plasmas
复制标题
弱碰撞等离子体中圆柱形探针的离子收集
DOI：
10.1063/1.1587889
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
M. Lampe
中科院分区：
文献类型：
--
作者：
Z. Sternovsky;S. Robertson;M. Lampe
一种理论方法最近被描述[Z。斯特诺夫斯基，S.罗伯逊和M.兰普，物理学家。《等离子体学报》（2003）[j]，在圆柱朗缪尔探测器的轨道运动限制理论中纳入了离子碰撞的影响。在单离子等离子体中，离子中性电荷交换碰撞占主导地位，它们的一级效应是增加收集的离子流的大小。对等离子体密度<109 cm−3的氩和氖气体放电的测量表明，该理论仅对半径小于德拜长度约一半的探针是准确的。对于较大的探针，离子在探针表面的吸收降低了局部的离子密度，导致鞘膨胀。这增加了收集电荷交换离子的体积，并进一步增加了离子电流。当探针靠近电离源放置时，测量结果和理论之间的不一致也被发现。
A theoretical approach has recently been described [Z. Sternovsky, S. Robertson, and M. Lampe, Phys. Plasmas 10, 300 (2003)] for including the effect of ion collisions in the orbit motion limited theory for cylindrical Langmuir probes. In plasmas with a single ion species, ion-neutral charge exchange collisions are dominant and their first order effect is to increase the magnitude of the collected ion current. Measurements in Ar and Ne gas discharges at plasma densities <109 cm−3 show that the theory is accurate only for probes with radii less than approximately half the Debye length. For larger probes, absorption of ions at the probe surface reduces the ion density locally causing the sheath to expand. This increases the volume from which the charge exchange ions are collected and further increases the ion current. Poor agreement between measurements and theory is also found, when the probe is placed close to the ionization source.