Université de Fribourg

Double K-shell photoionization and hypersatellite x-ray transitions of 12⩽Z⩽23 atoms

Hoszowska, Joanna ; Dousse, Jean-Claude ; Cao, Wei ; Fennane, Karima ; Kayser, Yves ; Szlachetko, Monika ; Szlachetko, Jakub ; Kavčič, Matjaz

In: Physical Review A, 2010, vol. 82, no. 6, p. 063408

Single-photon double K-shell ionization of low-Z neutral atoms in the range 12⩽Z⩽23 is investigated. The experimental method was based on measurements of the high- resolution Kαh hypersatellite x-ray spectra following the radiative decay of the K-shell double-vacancy states excited by monochromatic synchrotron radiation. The photon energy dependence of the double K-shell ionization was...

Université de Fribourg

Single-photon double K-shell ionization of low-Z atoms

Hoszowska, Joanna ; Kheifets, A. S. ; Dousse, Jean-Claude ; Bray, Igor ; Cao, Wei ; Fennane, Karima ; Kayser, Yves ; Kavčič, Matjaz ; Szlachetko, Jakub ; Szlachetko, Monika

In: Journal of Physics: Conference Series, 2010, vol. 212, no. 1, p. 012006

The photon energy dependence of the double K-shell ionization of light atoms is reported. Experimental double-to-single photoionization cross section ratios for Mg, Al, Si and Ca were obtained from measurements of high-resolution x-ray emission spectra. The double photoionization (DPI) cross-sections for K-shell hollow atom production are compared to convergent close-coupling calculations (CCC)...

Université de Fribourg

Double K-shell photoionization of low-Z atoms and He-like ions

Hoszowska, Joanna ; Kheifets, A. S. ; Berset, Michel ; Bray, I. ; Cao, Wei ; Dousse, Jean-Claude ; Fennane, Karima ; Kavčič, M. ; Kayser, Yves ; Szlachetko, Jakub ; Szlachetko, Monika

In: The European Physical Journal: Special Topics, 2009, vol. 169, no. 1, p. 23-27

We report on the investigation of the photon energy dependence of double 1s photoionization of light atoms and compare the cross sections for hollow atom and He-like ion production. Measurements of the Kα hypersatellite x-ray spectra of Mg, Al, and Si were carried out using the Fribourg high-resolution x-ray spectrometer installed at the ID21 and ID26 beam lines at the ESRF. The...

Université de Fribourg

Double K-shell ionization of Al induced by photon and electron impact

Fennane, Karima ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Berset, Michel ; Cao, Wei ; Maillard, Yves-Patrick ; Szlachetko, Jakub ; Szlachetko, Monika ; Kavčič, M.

In: Physical Review A, 2009, vol. 79, no. 3, p. 032708

This paper reports on the investigation of the double K-shell ionization of metallic aluminum induced by photon and electron impact. The experimental method consisted to measure the Kα hypersatellite spectra resulting from the radiative decay of double 1s vacancy states by means of high-resolution x-ray spectroscopy using a Bragg-type von Hamos crystal spectrometer....

Université de Fribourg

Physical mechanisms and scaling laws of K-shell double photoionization

Hoszowska, Joanna ; Kheifets, A. K. ; Dousse, Jean-Claude ; Berset, Michel ; Bray, I. ; Cao, Wei ; Fennane, Karima ; Kayser, Yves ; Kavčič, Matjaz ; Szlachetko, Jakub ; Szlachetko, Monika

In: Physical Review Letters, 2009, vol. 102, no. 7, p. 073006

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...

Université de Fribourg

Chemical effects in the Kβ X-ray emission spectra of sulfur

Kavčič, Matjaz ; Dousse, Jean-Claude ; Szlachetko, Jakub ; Cao, Wei

In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007, vol. 260, no. 2, p. 642-646

In this work our previous study about chemical effects in the Kα spectra of S compounds employing high-resolution X-ray spectroscopy has been extended to the Kβ emission spectra. The measurements were performed with a wavelength dispersive single crystal spectrometer operated in the von Hamos geometry having an energy resolution comparable to the natural linewidth of the measured Kβ X-ray...