PHOTOIONIZATION EXPERIMENTS ON ATOMIC PT IN THE RANGE 40-90-EV

The relative cross sections for single and double photoionization of t he refractory element platinum have been measured in the range of the 4f and 5p excitations using synchrotron radiation, an atomic beam prod uced by thermal evaporation, and a pulsed field time-of-flight techniq ue. The total photoionization cross section has been calculated with a relativistic Hartree-Fock method. The result is compared to the total ion yield and shows good agreement. A tentative assignment of the tra nsitions giving the main contributions to the cross section is made. T he ratio of the direct (5p + 4f) and (5d + 6s) ionization is calculate d and compared to the relative amount of double ionization.