Collinear laser spectroscopy on neutron-rich actinium isotopes

Ruohong Li; Andrea Teigelhöfer; Jiguang Li; Jacek Bieroń; András Gácsbaranyi; Jake Johnson; Per Jönsson; Victoria Karner; Mingxuan Ma; Martin Radulov; Mathias Roman; Monika Stachura; Jens Lassen

arXiv · 2503.13732

Collinear laser spectroscopy on neutron-rich actinium isotopes

Ruohong Li·Andrea Teigelhöfer·Jiguang Li·Jacek Bieroń·András Gácsbaranyi·Jake Johnson·Per Jönsson·Victoria Karner·Mingxuan Ma·Martin Radulov·Mathias Roman·Monika Stachura·Jens Lassen

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Abstract

High-resolution collinear laser spectroscopy of neutron-rich actinium has been performed at TRIUMF's isotope separator and accelerator facility ISAC. By probing the $7s^2~^1S_0$ $\rightarrow$ $6d7p~^1P_1$ ionic transition, the hyperfine structures and optical isotope shifts in $^{225, 226, 228, 229}\!$Ac$^+$ have been measured. This allows precise determinations of the changes in mean-square charge radii, magnetic dipole moments, and electric quadrupole moments of these actinium isotopes. The improved precision of charge radii and magnetic moments clears the ambiguity in the odd-even staggering from previous studies. The electric quadrupole moments of $^{225, 226, 228, 229}\!$Ac are determined for the first time.

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Ruohong Li, Andrea Teigelhöfer, Jiguang Li, Jacek Bieroń, András Gácsbaranyi, Jake Johnson, Per Jönsson, Victoria Karner, Mingxuan Ma, Martin Radulov, Mathias Roman, Monika Stachura, Jens Lassen. 2025-03-17. Collinear laser spectroscopy on neutron-rich actinium isotopes. https://arxiv.org/abs/2503.13732

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