Simple and effective techniques for loading barium ions into linear Paul traps are demonstrated. Two-step photoionization of neutral barium is achieved using a weak intercombination line ($6s^2{}^{1}S_0\leftrightarrow 6s6p{}^{3}P_1$, $\lambda =791\mathrm{nm}$) followed by excitation above the ionization threshold using a nitrogen gas laser $(\lambda =337\mathrm{nm})$. Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet $6s6p{}^{3}P_1$ state. Additionally, we report a particularly simple and efficient trap loading technique that employs an inexpensive uv epoxy curing lamp to generate photoelectrons.

• Received 17 February 2007

DOI:https://doi.org/10.1103/PhysRevA.75.053404