https://doi.org/10.1140/epja/s10050-024-01362-y
Regular Article - Experimental Physics
High-resolution laser spectroscopy on the hyperfine structure and isotope shift of 
Np
1
Institute of Physics, Johannes Gutenberg University Mainz, 55099, Mainz, Germany
2
Division Hübner Photonics, Hübner GmbH & Co. KG, 34123, Kassel, Germany
3
Department of Physics, University of Gothenburg, SE-41296, Gothenburg, Sweden
4
Department of Chemistry—Nuclear Chemistry, Johannes Gutenberg University Mainz, 55099, Mainz, Germany
5
GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany
6
Helmholtz Institute Mainz, 55099, Mainz, Germany
Received:
18
March
2024
Accepted:
14
June
2024
Published online:
1
July
2024
Nuclear ground state properties of Np were investigated by high-resolution laser spectroscopy at the RISIKO mass separator off-line radioactive beam facility of the University of Mainz. The isotope shifts and the hyperfine parameters were determined in two different atomic ground-state transitions at 398.80 nm and 395.61 nm. The data allowed for calculation of the so far unknown nuclear moments of the short-lived isotope 
Np, i.e. the nuclear magnetic dipole moment of 
= +3.18(2) 
and the electric quadrupole moment of 
= +4.05(8) eb, using the known nuclear moments of 
Np as a reference, which were determined by electron paramagnetic resonance and investigations of muonic X-ray hyperfine structures, respectively.
© The Author(s) 2024
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