Development and characterization of high-repetition-rate sources for supersonic beams of fluorine radicals

Patrik Straňák; Ludger Ploenes; Simon Hofsäss; Katrin Dulitz; Frank Stienkemeier; Stefan Willitsch

doi:10.1063/5.0065498

Development and characterization of high-repetition-rate sources for supersonic beams of fluorine radicals

Rev Sci Instrum. 2021 Oct 1;92(10):103203. doi: 10.1063/5.0065498.

Authors

Patrik Straňák¹, Ludger Ploenes¹, Simon Hofsäss², Katrin Dulitz², Frank Stienkemeier², Stefan Willitsch¹

Affiliations

¹ Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland.
² Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany.

PMID: 34717376
DOI: 10.1063/5.0065498

Abstract

We present and compare two high-pressure, high-repetition-rate electric-discharge sources for the generation of supersonic beams of fluorine radicals. The sources are based on dielectric-barrier-discharge (DBD) and plate-discharge units attached to a pulsed solenoid valve. The corrosion-resistant discharge sources were operated with fluorine gas seeded in helium up to backing pressures as high as 30 bars. We employed a (3 + 1) resonance-enhanced multiphoton ionization combined with velocity-map imaging for the optimization, characterization, and comparison of the fluorine beams. Additionally, universal femtosecond-laser-ionization detection was used for the characterization of the discharge sources at experimental repetition rates up to 200 Hz. Our results show that the plate discharge is more efficient in F₂ dissociation than the DBD by a factor between 8 and 9, whereas the DBD produces internally colder fluorine radicals.