Speaker
Description
Many studies are available discussing ion-neutral reactions at low temperatures, while mutual neutralization reactions (MN) are still experimentally rare. However, these anion-cation reactions play a crucial role in the chemistry of the interstellar medium. Models of these clouds rely heavily on their reaction rate coefficients [T. J. Millar $\textit{et al.}$, Chem. Rev. 117, (2017)]. In the literature the majority of these reactions are assigned the same rate coefficient, which is an approximation [N. S. Shuman $\textit{et al.}$, J. Phys.: Conf. Ser. 300 (2011)]. We will address this by measuring MN reactions of abundant ions in the interstellar space. Additionally, these systems can be used for benchmarking theoretical calculations of MN reactions [M. Roy $\textit{et al.}$, J. Chem. Phys., 2025]. To achieve this, we will utilize our cryogenic 16-pole wire trap, which is designed to create a relatively flat potential with steep walls [M. Nötzold $\textit{et al.}$, Phys. Rev. A, 106 (2022)]. The wires of the trap are driven with an RF voltage to contain the ions radially. A DC voltage is usually applied to endcap electrodes for axial confinement, but this only works for one charge polarity at a time. To investigate MN reactions, we will also drive the axial confinement using an RF voltage. With this trap we control the temperature and density to simulate different environments. The large expected cross section due to the attractive Coulomb potential will be offset by the low densities in the ion trap. Therefore, long storage times are essential. Our group has already demonstrated long trapping lifetimes for three-body reaction studies [C. Lochmann $\textit{et al.}$, J. Phys. Chem. A, 127 (2023)]. The status of the experiment will be reported.