Binary recombination of para- and ortho-${\rm{H}}_{\rm{3}}^{\rm{ + }}$with electrons at low temperatures

• Published in: Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences Vol. 370; no. 1978; pp. 5101 - 5108
• Main Authors: Dohnal, P., Hejduk, M., Varju, J., Rubovič, P., Roučka, Š., Kotrík, T., Plašil, R., Johnsen, R., Glosík, J.
• Format: Journal Article
• Language: English
• Published: The Royal Society 13-11-2012
• Subjects: Coefficients; Density; Electrons; Hydrogen; Ionization afterglow; Ions; Mass spectroscopy; Recombination coefficient; Spectroscopy; Temperature dependence
• ISSN: 1364-503X

Results of an experimental study of binary recombination of para- and ortho- ${\rm{H}}_{\rm{3}}^{\rm{ + }}$ ions with electrons are presented. Near-infrared cavity-ring-down absorption spectroscopy was used to probe the lowest rotational states of ${\rm{H}}_{\rm{3}}^{\rm{ + }}$ ions in the temperature range of 77-200 K in an ${\rm{H}}_{\rm{3}}^{\rm{ + }}$ -dominated afterglow plasma. By changing the para/ortho abundance ratio, we were able to obtain the binary recombination rate coefficients for pure para- ${\rm{H}}_{\rm{3}}^{\rm{ + }}$ and ortho- ${\rm{H}}_{\rm{3}}^{\rm{ + }}$ . The results are in good agreement with previous theoretical predictions.