Regular Article

Photodetachment in cold ion traps

Rotational state selective C₂H⁻ losses from quantum dynamics^★

¹ Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria
² Departamento de Química Física, University of Salamanca, Plaza de los Caídos sn, 37008 Salamanca, Spain

^a e-mail: francesco.gianturco@uibk.ac.at

Received: 21 January 2020
Received in final form: 21 April 2020
Published online: 25 June 2020

Abstract

We present a computational investigation of the photodetachment (PD) dynamics of C₂H⁻ in its ground, electronic ¹Σ state, cooled in an ion trap with He as a buffer gas. Our analysis employs a range of PD rates from quantum dynamics, selective choices of the anion’s initial rotational state populations as the laser is switched on, and different operational trap conditions. Our results show that a variety of outcomes for the initial state-dependent PD process is possible by selecting different initial conditions in the cold trap, the latter generating a dynamical interplay between the anion’s populations of rotational states, induced by the buffer gas, and the chosen laser frequency and laser power. Specific parameter selections during the PD process will be shown to cause different abundances of the rotational states of the anion in the trap.