We report a method of creating pure 9Be+ ions by a 2+1 resonance-enhanced multiphoton ionization (REMPI) for the ionization potential of 75192.64(6) cm-1 (133 nm). The efficient generation of 9Be+ ions has been realized in a segmented linear ion trap. The average loading rates with a 10 ns, 1 mJ laser at 310 nm and 306 nm are 3.8 and 1.3 ions per pulse, respectively. This method has the advantage of reducing the electron contamination to the ion trap electrodes greatly. It also reduces the requirement of single-photon energy while satisfying the need for ionization probability and can be applied to other atoms with high ionization thresholds.

We study the spatial structure and sympathetic cooling of the bi-component Coulomb crystal (CC) which consists of approximate 450 9Be+ ions and 450 40Ca+ ions with a mass ratio of 0.225 in a segmented linear ion trap. By two-dimensional imaging of the bi-component CC, the 9Be+ ions are found to be surrounded by the 40Ca+ ions in the radial direction with a separation ratio of ~2.0, and the axial length of the 9Be+ ions occupied area is much larger than that of the 40Ca+ ions occupied area. Combined with the previous experimental results, the structure of the 9Be+-40Ca+ CC shows the larger the difference in the mass-charge ratio, the larger the separation between the two species. The comparison of the fluorescence spectra of the 9Be+ ions in the bi-component CC and the pure CC indicates that the 9Be+ ions can be sympathetically cooled and stably localized by the laser-cooled 40Ca+ ions during the recording of the fluorescence spectrum.