The isotope shift, magnetic moment, and quadrupole moment of the radioactive transitional nucleus ${}_{}{}^{151}{}_{}{}^{}\mathrm{Sm}$ has been measured using the atomic-beam resonance-fluorescence technique. The hyperfine structure of the 591.6 nm transition was observed with an energy resolution of 20 MHz. The isotope shift of this line is found to be δ${\nu }_i^{151}$,152=-1472.2± 2.9 MHz. We have constructed a King plot of muonic atom δ〈$r^2$〉 versus optical isotope shifts to determine electronic parameters, and obtain δ〈$r^2$${〉}^{151}$,152=0.279±0.012 ${\mathrm{fm}}^2$.

• Received 7 September 1984

DOI:https://doi.org/10.1103/PhysRevC.31.240