Mevlut Dogan

Simultaneous excitation-ionization of helium to the state

Simultaneous excitation-ionization of helium to the ionic state by electron impact is studied experimentally and theoretically. Electron-photon angular correlations measured at an incident electron energy of 200 eV and electron scattering angles between and are in reasonable agreement with theoretical predictions. The double-differential cross section shows structure due to interference effects arising from autoionization states decaying into this channel. The emission cross section from threshold to 300 eV is also reported and compared with previous data.

Double Differential Cross Section Measurements for Electron Impact Ionization of Atmospheric Gases

We present comprehensive experimental measurements of double differential cross sections (DDCS) for atmospheric gases, Ar, N2, CO2 and CH4. DDCSs were obtained by measuring the energy and angular distributions of one of the two outgoing electrons which are indistinguishable by use traditional electron spectrometer with an electron analyzer.

Correlation Studies of Two Active-Atomic-Electron Ionization Processes in Free Atoms

During the last decade major advances have been made in the modelling of low energy inelastic scattering processes involving a single atomic electron. Experimental correlation studies of these processes have exposed the inadequacies of earlier calculations and played a key role in providing sensitive tests of the new theoretical approaches. Interest, both experimental and theoretical, is now turning to the more difficult problems involving two active atomic electron processes. The latest developments in this area are discussed with emphasis on double excitation-autoionization and simultaneous excitation-ionization.

Experimental Progress in Simultaneous Ionization‐Excitation Processes

A number of experimental techniques are now being used in different laboratories to study electron impact simultaneous ionization‐excitation in atoms. Here experimental studies, mostly from this laboratory, using the (e,eγ) and (e,2e) techniques are discussed. Data are presented for the He+(n = 2, 3, 4) states and the Ca+(4p) 2P3/2 state.