Isotope shifts of neutron-deficient gold isotopes with 193≧A≧190

The isotope shift between¹⁹⁷Au (stable) and the radioactive Au isotopes¹⁹⁰Au,¹⁹¹Au,¹⁹²Au and¹⁹³Au were determined by resonance fluorescence spectroscopy in the 6s ² S _1/2–6p ² P _1/2.λ=267.6nm line. The unstable Au isotopes were produced at the ISOLDE mass separator at CERN. The nuclei were investigated semi on-line in a resonance vessel, heated to 1,400°C. The results areδν ^190,197=?11.12(39) GHz,δν ^191,197=?9.67(12) GHz,δν ^192,197=?8.32(15) GHz,δν ^193,197=?6.29(11) GHz, corresponding to a change of the mean-square charge radius byδ〈r ²〉^190,197 =0.261(12) fm²,δ〈r ²〉^191,197=0.227(5) fm²,δ〈r ²〉^192,197=0.195(5) fm²,δ〈r ²〉^193,197 =0.148(4) fm².