Alfvén’s Critical Velocity Effect Tested in Space
Alfvén’s Critical Velocity Effect Tested in Space
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阿尔芬的临界速度效应在太空中经过测试
DOI：
10.1515/zna-1982-0803
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
G. Haerendel
中科院分区：
文献类型：
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作者：
G. Haerendel
一个探空火箭实验，涉及在电离层上部注入钡气体射流提供了一个机会，定量调查的几个方面的束等离子体相互作用，是阿尔芬的临界速度效应的物质。虽然实验数据在别处提供，本文包含了一些理论上的考虑（1）的限制中性密度的电离过程可以操作，（2）新鲜注入的离子与背景等离子体的相互作用，和（3）的微过程，导致无碰撞的电子尾形成。观察到的注入离子的分布是一致的汤森条件下的束等离子体放电。环境等离子体上的质量负载，虽然局部高，有一个弱的影响所涉及的磁通管的动态，因为有限的范围内的光束。能量从新产生的离子转移到电子的最可能的过程是离子束不稳定性，导致激发较低的混合波
A sounding rocket experiment involving the injection of a barium gas jet in the upper ionosphere provided an opportunity of investigating quantitatively several aspects of the beam-plasma interaction that is the substance of Alfven’s critical velocity effect. Whereas the experimental data are presented elsewhere, this paper contains some theoretical considerations of (1) the limiting neutral density for which the ionization process can operate, (2) the interaction of the freshly injected ions with the background plasma, and (3) the microprocess which leads to collisionless electron tail formation. The observed distribution of injected ions is consistent with the Townsend condition on the beam-plasma discharge. The mass loading on the ambient plasma, although locally high, has a weak effect on the dynamics of the involved flux-tube because of the limited extent of the beam. The most likely process by which energy is transferred from the freshly generated ions to the electrons is an ion beam instability leading to the excitation of lower hybrid waves