Gas-phase thorium clusters from laser ablation suggest magicity of Th

Paul Fischer; Jonas Stricker; Christoph E. Düllmann; Dennis Renisch; Lutz Schweikhard

doi:10.1140/epjd/s10053-025-00983-2

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2023 Impact factor 1.5

Atomic, Molecular, Optical and Plasma Physics

Open Access

Eur. Phys. J. D (2025) 79: 30
https://doi.org/10.1140/epjd/s10053-025-00983-2

Regular Article – Clusters and Nanostructures

Gas-phase thorium clusters from laser ablation suggest magicity of Th $_{13}^{+}$ $_{13}^+$

Paul Fischer¹^a, Jonas Stricker²^,3, Christoph E. Düllmann²^,3^,4, Dennis Renisch²^,3 and Lutz Schweikhard¹

¹ Institut für Physik, Universität Greifswald, 17487, Greifswald, Germany
² PRISMA+ Cluster of Excellence and Department of Chemistry, Johannes Gutenberg University Mainz, 55099, Mainz, Germany
³ Helmholtz-Institut Mainz, 55099, Mainz, Germany
⁴ GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany

^a paul.fischer@uni-greifswald.de

Received: 19 February 2025
Accepted: 8 March 2025
Published online: 4 April 2025

Abstract

Laser ablation of a metallic thorium foil produces cationic thorium clusters Th $_{n}^{+}$ $$_n^+$$ composed of up to $n = 15$ $$n=15$$ atoms as well as oxide clusters Th $_{n}$ $$_n$$ O $_{m}^{+}$ $$_m^+$$ . Mass spectra are recorded using a multi-reflection time-of-flight analyzer. Up to $n ≲ 8$ $n\lesssim 8$ , the most abundant species for a given cluster size is the Th $_{n}$ $$_n$$ O $_{2 n - 1}^{+}$ $_{2n-1}^+$ configuration. Notably, pure thorium clusters Th $_{n}^{+}$ $$_n^+$$ become dominant for $n ≳ 9$ $$n > rsim 9$$ . Production drops sharply after Th $_{13}^{+}$ $_{13}^+$ indicating increased relative stability associated with a “magic number” cluster size.

© The Author(s) 2025

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