SAMOP 2023 – scientific programme

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A: Fachverband Atomphysik

A 27: Poster III

A 27.20: Poster

Thursday, March 9, 2023, 16:30–19:00, Empore Lichthof

Ion-atom-atom collisions: from plasma physics to cold chemistry — •Marjan Mirahmadi¹ and Jesús Pérez-Ríos^1,2,3 — ¹Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany — ²Department of Physics, Stony Brook University, NY, USA — ³Institute for Advanced Computational Science, Stony Brook University, NY, USA

We present a study on ion-atom-atom reaction A+A+B⁺ in a wide range of systems and collision energies ranging from 100 µK to 10⁵ K, analyzing the two possible products: molecules (A₂) and molecular ions (AB⁺). The dynamics is performed via a direct three-body formalism based on a classical trajectory method in hyperspherical coordinates developed in [J. Chem. Phys. 140, 044307 (2014)]. Our chief finding is that the dissociation energy of the molecular ion product acts as a threshold energy separating the low and high energy regimes. In the low energy regime, the long-range tail of the three-body potential dictates the main reaction product. On the contrary, in the high energy regime, the short-range of atom-atom and atom-ion interaction potential dominates the dynamics, enhancing molecular formation for the low energy regime. Moreover, we are able to confirm the previously derived threshold law for ion-neutral-neutral three-body recombination in [J. Chem. Phys. 143, 041105 (2015); Phys. Rev. A 98, 062707 (2018)] at low temperatures and establish the range of its validity.