Dohnal Petr, Shapko Dmytro, Kálosi Ábel, Kassayová Miroslava, Roučka Štěpán, Rednyk Serhiy, Plašil Radek, Hejduk Michal, Glosík Juraj
Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Charles University, V Holešovičkách 2, 180 00 Praha 8-Libeň, Czech Republic.
Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford, OX1 3QZ, UK.
Faraday Discuss. 2019 Jul 18;217(0):220-234. doi: 10.1039/c8fd00214b.
We present studies on the thermalisation of H3+ ions in a cold He/Ar/H2 plasma at temperatures 30-70 K. We show that we are able to generate a rotationally thermalised H3+ ensemble with a population of rotational and nuclear spin states corresponding to a particular ion translational temperature. By varying the para-H2 fraction used in the experiment we are able to produce para-H3+ ions with fractional populations higher than those corresponding to thermodynamic values. At 35 K, only the lowest rotational states of para and ortho H3+ are populated. This is the first step towards experimental studies of electron-molecular ion recombination processes with precisely specified quantum states at astrophysically relevant temperatures.
我们展示了关于在30 - 70 K温度下，H₃⁺离子在冷He/Ar/H₂等离子体中的热化研究。我们表明，我们能够产生一个转动热化的H₃⁺系综，其转动和核自旋态的分布对应于特定的离子平动温度。通过改变实验中使用的仲氢（para-H₂）比例，我们能够产生分数布居高于热力学值对应的分数布居的仲H₃⁺离子。在35 K时，只有仲H₃⁺和正H₃⁺的最低转动态被占据。这是朝着在天体物理相关温度下对具有精确指定量子态的电子 - 分子离子复合过程进行实验研究迈出的第一步。
