This work addresses the negative ionization of hydrogen particles on low work function metal surfaces, which is an important process for the field of the surface plasma negative ion beams sources. We present the theoretical model for the computer calculation of the negative ionization probability which takes into account the component of atom/ion velocity, parallel to the surface. The calculated negative ionization probability of hydrogen quantitatively fits to the experimental data in the wide range of ion exit energies. The theoretical estimation shows, that for the low work function converter surfaces (φ∼1.5 eV) the negative ionization probability of hydrogen can be enhanced up to 30% if the hydrogen has velocity component parallel to the surface ∼0.05 a.u. (∼60 eV). Therefore, the H^- ion production rate can be increased for a negative ion source configuration that implements the oblique exit angle of hydrogen.

这项工作解决了低逸出功金属表面氢粒子的负电离问题，这是表面等离子体负离子束源领域的一个重要过程。我们提出了计算机计算负电离概率的理论模型，该模型考虑了平行于表面的原子/离子速度分量。计算出的氢负电离概率在很宽的离子出口能量范围内定量地符合实验数据。理论估计表明，对于低功函数转换器表面（φ ∼1.5 eV），如果氢具有平行于表面的速度分量∼0.05 au (∼60 eV)，则氢的负电离概率可以提高高达 30% . 因此，H ^- 对于实施氢气倾斜出口角的负离子源配置，可以增加离子产生速率。