Probing charge-transfer neutralization reactions of atmospheric importance using the ion storage facility DESIREE

The Double ElectroStatic Ion Ring ExpEriment (DESIREE) facility located at Stockholm University, Sweden, uniquely allows for studies of mutual neutralization interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 20 K and ~50 meV, respectively [1-3].

Using this facility, we aim for a better understanding of how small and large molecules are formed and processed in astrophysical, atmospheric, and combustion plasmas, where we combine several novel experimental methods to build a fundamental picture of the transfer of charge-, energy- and mass in collisional reactions. Control over the reaction environment [1-6] means that desired information, e.g., reaction products, can be obtained over many of the conditions needed to accurately model plasmas where these processes are important.

Here, I highlight how this facility can play a crucial role in studying in mutual neutralization reactions relevant to cool atmospheric plasmas: providing insights into ion balance processes, and, e.g., in the production of F-layer UV airglows. I focus on reactions involving the primary atomic and molecular oxygen and nitrogen ions [4,5], i.e., O^- + O⁺, O^- + N⁺, O^- + NO⁺, O^- + O₂⁺, and O^- + N₂⁺, where, in the processes with molecular cations, I can further determine the fractionation into two- and three-body product channels and study the effects of the rovibrational energy of the molecular ion on the reaction process.



References

[1] R. D. Thomas et al., Rev. Sci. Instrum. 82, 065112 (2011)

[2] H. T. Schmidt et al., Rev. Sci. Instrum. 84, 055115 (2013)

[3] H. T. Schmidt et al., Phys. Rev. Lett. 119, 073001 (2017)

[4] M. Poline et al. Phys. Chem. Chem. Phys. 23, 24607 (2021)

[5] M. Poline et al. Phys. Rev. A, 105, 062825 (2022)

[6] M. Poline et al. Phys. Rev. A, 106, 012812 (2022)