Resonant laser ionization of neptunium: investigation on excitation schemes and the first ionization potentialMagdalena Kaja, Dominik Studer, Felix Berg, Sebastian Berndt, Christoph E. Düllmann, Nina Kneip, Tobias Reich, Mitzi Urquiza-González and Klaus WendtEur. Phys. J. D, 78 5 (2024) 50DOI: https://doi.org/10.1140/epjd/s10053-024-00833-7