Associative Detachment of H$^{-$ + H $\to$ H${}_2$ + e${}^{-}$

Abstract

Using a merged beams apparatus we have measured the associative detachment (AD) reaction of ${\mathrm{H}}^{-}+\mathrm{H}\to {\mathrm{H}}_2+e^{-}$ for relative collision energies up to \textit{E}${}_{\mathrm{r}}\le 4.83$ eV. These data extend above the 1 eV limit of our earlier results. We have also updated our previous theoretical work to account for AD via the repulsive ${}^2{\Sigma }_{\mathrm{g}}^{+}$ H${}_2^{-}$ potential energy surface and for the effects at $E_{\mathrm{r}}\ge 0.76$ eV on the experimental results due to the formation of H${}_2$ resonances lying above the $\mathrm{H}+\mathrm{H}$ separated atoms limit. Merging both experimental data sets, our results are in good agreement with our new theoretical calculations and confirm the prediction that this reaction essentially turns off for $E_{\mathrm{r}}\gtrsim 2$ eV. Similar behavior has been predicted for the formation of protonium from collisions of antiprotons and hydrogen atoms.

Accepted for publication Phys. Rev. A

References in corpus (2)

• Uncertainties in H2 and HD Chemistry and Cooling and their Role in Early Structure Formation
• Cosmological Implications of the Uncertainty in H- Destruction Rate Coefficients

Cited by in corpus (4)

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• Associative detachment in anion-atom reactions involving a dipole-bound electron