Ionization cross section, pressure shift and isotope shift measurements of osmium

Abstract

In-gas-cell laser resonance ionization spectroscopy of neutral osmium atoms was performed with the use of a two-color two-step laser resonance ionization technique. Saturation curves for the ionization scheme were measured, and the ionization cross section was experimentally determined by solving the rate equations for the ground, intermediate and ionization continuum populations. The pressure shift and pressure broadening in the resonance spectra of the excitation transition were measured. The electronic factor for the transition nm to the intermediate state was deduced from the measured isotope shifts of stable Os isotopes. The efficient ionization scheme, pressure shift, nuclear isotope shift and are expected to be useful for applications of laser ion sources to unstable nuclei and for nuclear spectroscopy based on laser ionization techniques.