Gas-phase thorium clusters from laser ablation suggest magicity of Th$$_{13}^+$$
Abstract Laser ablation of a metallic thorium foil produces cationic thorium clusters Th $$_n^+$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mi>n</mml:mi> <mml:mo>+</mml:mo> </mml:mmultiscripts> </mml:math> composed of up to $$n=15$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>n</mml:mi> <mml:mo>=</mml:mo> <mml:mn>15</mml:mn> </mml:mrow> </mml:math> atoms as well as oxide clusters Th $$_n$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mi>n</mml:mi> <mml:mrow/> </mml:mmultiscripts> </mml:math> O $$_m^+$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mi>m</mml:mi> <mml:mo>+</mml:mo> </mml:mmultiscripts> </mml:math> . Mass spectra are recorded using a multi-reflection time-of-flight analyzer. Up to $$n\lesssim 8$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>n</mml:mi> <mml:mo>≲</mml:mo> <mml:mn>8</mml:mn> </mml:mrow> </mml:math> , the most abundant species for a given cluster size is the Th $$_n$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mi>n</mml:mi> <mml:mrow/> </mml:mmultiscripts> </mml:math> O $$_{2n-1}^+$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>n</mml:mi> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> <mml:mo>+</mml:mo> </mml:mmultiscripts> </mml:math> configuration. Notably, pure thorium clusters Th $$_n^+$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mi>n</mml:mi> <mml:mo>+</mml:mo> </mml:mmultiscripts> </mml:math> become dominant for $$n > rsim 9$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>n</mml:mi> <mml:mo>≳</mml:mo> <mml:mn>9</mml:mn> </mml:mrow> </mml:math> . Production drops sharply after Th $$_{13}^+$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow> <mml:mn>13</mml:mn> </mml:mrow> <mml:mo>+</mml:mo> </mml:mmultiscripts> </mml:math> indicating increased relative stability associated with a “magic number” cluster size. Graphical abstract
Authors
- Jonas Stricker (ORCID: https://orcid.org/0009-0008-4972-6044)
- Ch. E. Düllmann (ORCID: https://orcid.org/0000-0002-1194-0423)
- Dennis Renisch (ORCID: https://orcid.org/0000-0001-8561-0016)
- Paul Fischer (ORCID: https://orcid.org/0000-0002-1985-313X)
- L. Schweikhard (ORCID: https://orcid.org/0009-0002-8272-0388)
Institutions
- GSI Helmholtz Centre for Heavy Ion Research (DE)
- Johannes Gutenberg University Mainz (DE)
- Universität Greifswald (DE)
- Helmholtz Institute Mainz (DE)
Publication Details
- Journal
- The European Physical Journal D
- Published
- 2025-04-01
- DOI
- https://doi.org/10.1140/epjd/s10053-025-00983-2
- Citations
- 1
- Primary Topic
- Cold Atom Physics and Bose-Einstein Condensates
- Type
- article
- Field-Weighted Citation Impact
- 1.25
Funders
- Deutsche Forschungsgemeinschaft