Generation of an indium ion beam by selective multistage laser photoionization of atoms

The method of selective two-stage photoionization of atoms by a dye laser was used to generate an indium ion current of 5 μ A. The dye laser was pumped by copper vapor laser radiation in the form of pulses with a repetition frequency of 8 kHz. The dye laser radiation was absorbed completely during the first stage of the photoionization process. The photoionization cross section of the excited state was σ₂=(6.1±0.6)×10^–18 cm².