Transition frequencies, isotope shifts, and hyperfine structure in 4s→4p transitions of stable Ti+ ions

Abstract

We have measured transition frequencies, isotope shifts, and hyperfine-structure splittings in the $3d^2{(}^{3}F)4s{}^4{F}_J\to 3d^2{(}^{3}F)4p{}^4{G}_{J+1}^o$ transitions in stable ${\mathrm{Ti}}^{+}$ ions for $J=\frac{3}{2},\frac{5}{2},\frac{7}{2}$ using collinear laser spectroscopy. Ions were generated by laser ablation in a buffer-gas atmosphere and extracted into vacuum through a nozzle and a pair of radio-frequency funnels. The results obtained are of interest as reference values for on-line measurements of short-lived titanium isotopes and for astrophysical searches for temporal or spatial variations of the fine-structure constant $\alpha$ using quasar absorption spectra.