Photoionization and photoelectric loading of barium ion traps

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 (6s²0.2em0ex¹S₀↔6s6p0.2em0ex³P₁, λ=7910.3em0exnm) followed by excitation above the ionization threshold using a nitrogen gas laser (λ=3370.3em0exnm). Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet 6s6p0.2em0ex³P₁ state. Additionally, we report a particularly simple and efficient trap loading technique that employs an inexpensive uv epoxy curing lamp to generate photoelectrons.