Inner-shell ionization of atoms by electron, positron and photon impacts

Deep inner-shell multiphoton ionization by intense x-ray free-electron laser pulses.

We have investigated multiphoton multiple ionization dynamics of xenon atoms using a new x-ray free-electron laser facility, SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, and identified that Xe(n+) with n up to 26 is produced at a photon energy of 5.5 keV. The observed high charge states (n≥24) are produced via five-photon absorption, evidencing the occurrence of multiphoton a...

Ionization of K-shell electrons by electron or positron impact

The single ionization of inner-shell electrons by electron or positron impact are the fundamental processes, which still attract considerable interest in collision theory, experimental studies, and various applications. To predict the ionization cross sections, one usually employs either sophisticated numerical approaches or empirical and semiempirical formulas. Significant efforts have been al...

Single-photon multiple ionization processes studied by electron coincidence spectroscopy

This thesis is based on studies of multiple ionization of atoms and molecules induced by the absorption of a single photon. For the experimental investigations a time-of-flight magnetic bottle spectrometer has been used to detect the emitted electrons in coincidence. The method of coincidence time-of-flight spectroscopy and the experimental setup used is described. Experimental and theoretical ...

K-shell ionization of atoms by electron and positron impact.

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

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 Kα 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 measured o...