Abstract
We present state-selected measurements of rotational cooling and excitation rates of molecular ions by inelastic electron collisions. The experiments are carried out at a cryogenic storage ring, making use of a monoenergetic electron beam at matched velocity in combination with state-sensitive laser dissociation of the ions for simultaneous monitoring of the rotational level populations. Employing storage times of up to 600 s, we create conditions where electron-induced cooling to the ground state dominates over radiative relaxation, allowing for the experimental determination of inelastic electron collision rates to benchmark state-of-the-art theoretical calculations. On a broader scale, our experiments pave the way to probe inelastic electron collisions for a variety of molecular ions relevant in various plasma environments.
- Received 17 August 2021
- Revised 2 March 2022
- Accepted 23 March 2022
DOI:https://doi.org/10.1103/PhysRevLett.128.183402
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Open access publication funded by the Max Planck Society.
Published by the American Physical Society
Physics Subject Headings (PhySH)
synopsis
Electron-Ion Collisions Measured in a Cryogenic Facility
Published 4 May 2022
Researchers use lasers and extreme cooling to monitor the rotational states of molecular ions after they collide with electrons, confirming predictions about the rates of these collisions.
See more in Physics