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)