Double-resonant photoionization spectroscopy of SrI

We report on the investigation of the double-resonant photoionization of Sr atoms out of the ground state 5s(1)(2)S(0), and the metastable triplet sta tes 5s5p P-3(j0). Specifically, the saturation behavior of both the excitat ion steps to intermediate states, and the ionization steps to auto-ionizing states have been studied, and the photoionization cross-sections from the intermediate levels into auto-ionizing states were determined. The ionizati on schemes were applied in saturation conditions to estimate the ratio of a toms sputtered in the ground and metastable states during Ar+ ion-beam sput tering from a polycrystalline strontium target. (C) 2000 Elsevier Science B .V. All rights reserved.