Speaker
Description
Detailed insight into the dynamics of elementary reactions in the gas phase can be obtained from crossed-beam reactive scattering experiments. Angle and energy differential cross-section can be obtained by combining the velocity map imaging (VMI) with crossed-beam scattering[1][2]. In this contribution, we present the differential cross-section measurement of an ion-molecule charge transfer reaction of argon ions with neutral hydrogen molecules, imaged using VMI with rotationally resolved product distribution significantly improved over our previous study.
\begin{equation}
{Ar^+(^2P_{3/2}) + H_2(v=0,j=0,1) \xrightarrow{} H_2^+(v^\prime,j^\prime) + Ar(^1S_\circ) + 0.333\,eV \label{}\tag{1}}
\end{equation}
The ions were created in the spin-orbit ground state of Ar\textsuperscript{+} by Resonance Enhanced Multiphoton ionization (REMPI)[3]. The ions were produced with high energy resolution with our new experimental configuration of electrostatic lenses[4]. Chemical reactions are initiated by the beam of ions intersecting with the beam of neutral molecules generated in a supersonic expansion. The reaction products are collected by the new VMI spectrometer and then detected and imaged. The results show that high product rotational excitation is found, in contrast to reactions of spin-orbit excited Ar$^+(^2$P$_{1/2})$. Quantum scattering calculations are currently underway to describe the reaction.
References
[1] R. Wester Phys. Chem. Chem. Phys., vol. 16, pp. 396–405, 2014.
[2] T. Michaelsen, B. Bastian, E. Carrascosa, J. Meyer, D. H. Parker,and R. Wester J. Chem. Phys., vol. 147, no. 1, 2017.
[3] G. Zhang, D. Lu, Y. Ding, L. Guan, S. Han, H. Guo, and H. Gao Nat. Chem, vol. 15, no. 9, pp. 1255–1261, 2023.
[4] D. Swaraj, T. Michaelsen, A. Khan, F. Zappa, R. Wild, and R. Wester
Mol.Phys, vol. 122, no. 1-2, p. e2194455, 2024.
