Bright Source of Cold Ions for Surface-Electrode Traps*

We produce large numbers of low-energy ions by photoionization of laser-cooled atoms inside a surface-electrode-based Paul trap. The isotope-selective trap loading rate of $4\times10^{5}$ $^{174}$Yb$^{+}$ ions/s exceeds that attained by photoionization (electron impact ionization) of an atomic beam by four (six) orders of magnitude. Our high loading rate could enable rapid, isotope-selective loading of large ion trap arrays for use in quantum computing or atomic clocks. The ions are confined in the same spatial region as the laser-cooled atoms, which will also allow experimental investigation of the interactions between cold ions and cold atoms.