title: Physical mechanisms and scaling laws of K-shell double photoionization.
abstract: We report on the photon energy dependence of the K-shell double photoionization (DPI) of Mg, Al, and Si. The DPI cross sections were derived from high-resolution measurements of x-ray spectra following the radiative decay of the K-shell double vacancy states. Our data evince the relative importance of the final-state electron-electron interaction to the DPI. By comparing the double-to-single K-shell photoionization cross-section ratios for neutral atoms with convergent close-coupling calculations for He-like ions, the effect of outer shell electrons on the K-shell DPI process is assessed. Universal scaling of the DPI cross sections with the effective nuclear charge for neutral atoms is revealed.
authors.affiliation: Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Hoszowska
authors.forename: A K
authors.initials: AK
authors.lastname: Kheifets
authors.forename: J-Cl
authors.initials: JC
authors.lastname: Dousse
authors.forename: M
authors.initials: M
authors.lastname: Berset
authors.forename: I
authors.initials: I
authors.lastname: Bray
authors.forename: W
authors.initials: W
authors.lastname: Cao
authors.forename: K
authors.initials: K
authors.lastname: Fennane
authors.forename: Y
authors.initials: Y
authors.lastname: Kayser
authors.forename: M
authors.initials: M
authors.lastname: Kavcic
authors.forename: J
authors.initials: J
authors.lastname: Szlachetko
authors.forename: M
authors.initials: M
authors.lastname: Szlachetko