Optimal scheme for multistage photoionization of lutetium atoms by laser radiation

An experimental investigation was made of the even Rydberg and autoionizing states of lutetium atoms. These atoms were excited and ionized in two stages by radiation from tunable dye lasers. A study was made of the dependence of the ion current on the laser wavelength in the second stage. The results were used to propose an effective ionization scheme involving an autoionizing state with an excitation cross section of 1.5×10^–15 cm² .