Enhanced sensitivity for electron affinity measurements of rare elements
The electron affinity (EA), the energy released when a neutral atom binds an additional electron, is a fundamental property of atoms that is governed by electron-electron correlations and is strongly related to an element's chemical reactivity. However, conventional techniques for EA determination lack the experimental sensitivity to probe very scarce samples. As a result, the EA for the heaviest elements of the periodic table is entirely uncharted. Here, we present a novel technique to determine EAs through Laser Photodetachment Threshold Spectroscopy, performed in an electrostatic ion beam trap to increase the samples' exposure to laser photons and, thus, improve the experimental signal sensitivity by three orders of magnitude. Moreover, the additional exposure time allows the use of lower-power continuous-wave narrow-band lasers that reduce uncertainties associated with broadening effects induced by the laser bandwidth. By applying this technique, we measure the EA of <sup>35</sup>Cl to be 3.612720(44) eV, achieving state-of-the-art precision while employing five orders of magnitude fewer anions. The demonstrated sensitivity paves the way for systematic EA measurements across isotopic chains - including isotope shifts and hyperfine splittings - and ultimately for the first direct determination of electron affinities in superheavy elements.
Authors
- Jessica Warbinek (ORCID: https://orcid.org/0000-0002-2385-5584)
- M. Vilén (ORCID: https://orcid.org/0000-0002-0375-2502)
- L. V. Rodríguez (ORCID: https://orcid.org/0000-0002-0093-2110)
- S. Malbrunot-Ettenauer (ORCID: https://orcid.org/0009-0004-3323-6500)
- D. Leimbach (ORCID: https://orcid.org/0000-0002-4587-1067)
- S. Rothe (ORCID: https://orcid.org/0000-0001-5727-7754)
- U. Berzinsh (ORCID: https://orcid.org/0000-0003-3029-9296)
- E. Leistenschneider (ORCID: https://orcid.org/0000-0003-0377-8523)
- M. Reponen (ORCID: https://orcid.org/0000-0003-1298-7431)
- M. Au (ORCID: https://orcid.org/0000-0002-8358-7235)
- D. Hanstorp (ORCID: https://orcid.org/0000-0001-6490-6897)
- S. Lechner (ORCID: https://orcid.org/0000-0002-1695-5683)
- Y. N. Vila Gracia
- L. Schweikhard (ORCID: https://orcid.org/0009-0002-8272-0388)
- F.M. Maier (ORCID: https://orcid.org/0000-0001-9715-2147)
- Carina Kanitz (ORCID: https://orcid.org/0009-0001-2322-570X)
- V. Lagaki (ORCID: https://orcid.org/0000-0003-3068-6544)
- P. Plattner (ORCID: https://orcid.org/0000-0002-0479-3234)
Institutions
- TRIUMF (CA)
- Lawrence Berkeley National Laboratory (US)
- GSI Helmholtz Centre for Heavy Ion Research (DE)
- University of Toronto (CA)
- Johannes Gutenberg University Mainz (DE)
- Universitätsmedizin Greifswald (DE)
- Universität Greifswald (DE)
- Max Planck Institute for Nuclear Physics (DE)
- Facility for Rare Isotope Beams
- European Organization for Nuclear Research (CH)
- Michigan State University (US)
- University of Gothenburg (SE)
- University of Latvia (LV)
- University of Jyväskylä (FI)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-11-03
- DOI
- https://doi.org/10.1038/s41467-025-64581-x
- Primary Topic
- Atomic and Molecular Physics
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- U.S. Department of Energy
- TRIUMF
- CERN
- European Commission
- Bundesministerium für Bildung und Forschung
- Vetenskapsrådet
- Max Planck Institute for Nuclear Physics
- Office of Science
- Natural Sciences and Engineering Research Council of Canada
- Nuclear Physics