Abstract

Resonant mechanisms of electron–ion recombination accompanied by the formation of Rydberg atoms in a plasma containing atomic and molecular ions are investigated. An analytical approach is developed for the description of three-particle electron capture into a Rydberg state as a result of resonant energy transfer from a free electron to the electronic shell of a quasimolecular ion formed during the collision of an atomic ion with a buffer gas atom. An efficient method is proposed to calculate dissociative recombination rates under thermal excitation of all rotational–vibrational (rovibrational) levels of the molecular ion. The dependence of the cross sections and the rate constants of the processes on the principal quantum number is established, and the relative role of these processes is determined in a wide range of temperatures of the electron, T_e, and gas, T, components of the plasma. Conditions are found under which integral contributions of the continuous spectrum of the molecule and of the whole rovibrational quasicontinuum to the total rate of resonant electron capture are dominant. A specific analysis is carried out by an example of Ne + Xe⁺ + e and Ar + Xe⁺ + e heteronuclear systems with significantly different dissociation energies (D₀ = 33 and 171 meV) of the ground electronic term of the RgXe⁺ (Rg = Ne and Ar) ion. It is shown that the capture rate constants essentially depend on the binding energy |ε_n| of the resulting Xe(n) atom, the temperatures T and T_e, and the relationship between D₀ and the thermal energy k_BT.

中文翻译：

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离子将共振电子捕获到原子的里德堡态中

摘要

研究了在包含原子和分子离子的等离子体中电子-离子重组的共振机理以及里德堡原子的形成。开发了一种分析方法，用于描述三原子电子由于共振能量从自由电子转移到在原子离子与缓冲气体原子碰撞过程中形成的准分子离子的电子壳而转移到里德堡态的过程。提出了一种有效的方法来计算分子离子的所有旋转振动（摆动）能级在热激发下的解离重组率。确定了横截面和过程速率常数对主量子数的依赖性，并在电子的宽温度范围内确定了这些过程的相对作用，T _e和等离子体的气体T组成。发现了这样的条件，在该条件下，分子的连续光谱和整个旋转振动准连续谱对共振电子捕获的总速率的整体贡献占主导地位。通过一个N + Xe ⁺ + e和Ar + Xe ⁺ + e异核系统的实例进行了特定分析，该系统具有RgXe ⁺（Rg ）的地电子项的解离能（D ₀ = 33和171 meV）明显不同。= Ne和Ar）离子。结果表明，捕获速率常数主要取决于结合能|ε _ñ | 所得Xe（n）原子，温度T和T _e以及D ₀和热能k _B T之间的关系。