Influence of atom-atom collisions on the collisional-radiative ionization and recombination coefficients of helium plasmas
Influence of atom-atom collisions on the collisional-radiative ionization and recombination coefficients of helium plasmas
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DOI：
10.1007/bf01379781
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发表时间：
1972-06
期刊：
影响因子：
--
通讯作者：
H. Drawin;F. Emard
中科院分区：
文献类型：
--
作者：
H. Drawin;F. Emard
本文计算了低电离度稠密氦等离子体的体积复合和电离系数。计算是基于碰撞辐射模型，其中电子-原子，电子-电子-离子，原子-原子，和电子-原子-离子碰撞干预。未考虑分子物种，如He 2 * 和He 2+。主要成果如下：在低温和高中性气体密度下，复合系数与中性氦原子的数密度成正比。在高温下，与纯离子-电子-电子复合相比，中性粒子的存在实际上不影响复合过程。在高中性粒子密度、高原子温度和低电子密度下，电离过程主要是由于原子-原子碰撞。在这一点上，我们的计算与Kalra和Measures（Phys.Fluids14，2544（1971））最近的激波管测量结果比较一致。本文强调，惰性气体中激波电离的简单两步模型应被更一般的碰撞辐射模型所取代，在该模型中，原子能级结构更详细地介入。
Coefficients for volume recombination and ionization have been calculated for a dense helium plasma of low degree of ionization. The calculations are based on a collisional-radiative model in which electron-atom, electron-electron-ion, atom-atom, and electron-atom-ion collisions intervene. Molecular species such as He2*and He2+have not been taken into account. The essential results are: At low temperatures and high neutral gas densities the recombination coefficient is proportional to the number density of neutral helium atoms. At high temperatures the presence of neutral particles practically does not influence the recombination process compared to pure ion-electron-electron recombination. At high neutral particle densities, high atom temperatures and low electron densities the ionization process is mainly due to atom-atom collisions. In this point our calculations are in relatively good agreement with recent shock tube measurements of Kalra and Measures (Phys. Fluids14, 2544 (1971)). It is emphasized that the simple two-step model for ionization by shock waves in the noble gases should be replaced by a more general collisional-radiative model in which the atomic level structure intervenes in more detail.