Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, Prague 18000, Czech Republic.
J Chem Phys. 2012 Jun 28;136(24):244304. doi: 10.1063/1.4730162.
Measurements in H(3)(+) afterglow plasmas with spectroscopically determined relative abundances of H(3)(+) ions in the para-nuclear and ortho-nuclear spin states provide clear evidence that at low temperatures (77-200 K) para-H(3)(+) ions recombine significantly faster with electrons than ions in the ortho state, in agreement with a recent theoretical prediction. The cavity ring-down absorption spectroscopy used here provides an in situ determination of the para/ortho abundance ratio and yields additional information on the translational and rotational temperatures of the recombining ions. The results show that H(3)(+) recombination with electrons occurs by both binary recombination and third-body (helium) assisted recombination, and that both the two-body and three-body rate coefficients depend on the nuclear spin states. Electron-stabilized (collisional-radiative) recombination appears to make only a small contribution.
在 H(3)(+)余晖等离子体中的测量结果表明，通过光谱学确定的para-核和 ortho-核自旋状态下 H(3)(+)离子的相对丰度，低温（77-200 K）下 para-H(3)(+)离子与电子的复合速度明显快于 ortho 态离子，这与最近的理论预测一致。本文中使用的腔衰荡吸收光谱法提供了对 para/ortho 丰度比的原位测定，并为复合离子的平移和旋转温度提供了额外信息。结果表明，H(3)(+)与电子的复合通过双分子复合和三体（氦）辅助复合发生，并且双体和三体速率系数都取决于核自旋状态。电子稳定的（碰撞辐射）复合似乎只贡献很小一部分。
