An efficient excitation scheme for resonance ionization of tin in a laser ion source

Abstract

An efficient three-colour, three-step resonant excitation/ionization scheme has been found for tin that leads from the 5 p 2 3 P 2 level of the ground-state multiplet via two excited atomic levels (λ 1 = 317.51 nm and λ 2 = 811.40 nm) to an autoionizing state 9 s 3 P 2(λ 3 = 823.49 nm) at 59375.9 cm −1. This excitation path permits the saturation of all transitions with the limited power available from a copper vapour laser pumped dye laser system ( E sat ≈ 1.5 mJ cm 2 for λ 3). The high repetition rate of such a laser system is essential for a highly efficient laser ion source.