Nuclear moments and isotope shifts of the actinide isotopes Cf249–253 probed by laser spectroscopy

Abstract

We report on high-resolution laser spectroscopy studies on Cf249–253 with spectral linewidths in the order of 100 MHz carried out at the RISIKO mass separator at Mainz University. In total three atomic ground-state transitions were investigated and the hyperfine parameters for the odd-A isotopes and isotope shift for all examined isotopes have been determined from the measured spectra. The isotope shift measurements allowed tracking of changes in mean-squared charge radii across the deformed nuclear shell closure at N=152, whereby shape discontinuities were not observed. Experimental hyperfine coupling constants of the atomic ground state were combined with relativistic many-body atomic calculations to extract the nuclear magnetic-dipole moment of Cf249 with improved precision to μI(249Cf)=−0.395(17)μN, whereas μI(251Cf)=−0.571(24)μN and μI(253Cf)=−0.731(35)μN were derived for the first time. Additionally, the spectroscopic quadrupole moments QS(249Cf)=6.27(33)eb and QS(253Cf)=5.53(51)eb were extracted.Received 20 December 2022Accepted 7 February 2023DOI:https://doi.org/10.1103/PhysRevC.107.034313Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFine & hyperfine structurePropertiesA ≥ 220TechniquesAb initio calculationsRadioactive beamsNuclear Physics