V.V. Balashov

On the possibility of investigating atomic autoionizing states in coincidence experiments

Abstract The possibility of investigating atomic autoionizing states in coincidence experiments on inelastic scattering of fast particles is discussed. The calculations have been performed for the (2s 2p)1P(−)-state of helium.

Angular distribution of autoionization and Auger electrons ejected by electron impact from laser-excited and polarized atoms

A general formalism is developed for a description of the angular distribution of electrons ejected after the electron-impact excitation/ionization of the laser-excited and polarized atoms. Properties of the angular distributions are analysed in a general case as well as in some particular geometries of the experiment. Within the two-step approximation the formalism is applied to the resonant single and double ionization with ejection of autoionization and Auger electrons. As an example the angular distributions of autoionization electrons from laser-excited sodium atoms are calculated in the plane-wave and distorted-wave Born approximations. Angular correlations between autoionization and scattered electrons, which can be measured in a coincidence (e,2e) experiment with polarized targets, are also analysed.

Lifetimes of the metastable states of the lithium-like ions

Abstract The lifetime of the (1s2s2p)4 P 5 2 state of the lithium-like ions from Li to O5+ has been calculated using the screened Coulomb functions of the bound electrons. The lifetimes of the (1s2s2p)4 P 1 2 , 3 2 states in these ions have been evaluated. The theoretical results are compared with experiment [1,2].

Inelastic scattering of electrons from atoms in the multichannel diffraction approximation

The multichannel diffraction approximation is used to calculate differential and total cross sections for the excitation of the resonance transitions in Ne and Ar atoms by intermediate energy electrons. The correlation parameters lambda and chi have also been calculated. The results are compared with experimental data and other approximations.

Possibilities of diagonalization method for calculating the atomic system resonances

Abstract The photoionization of He below n = 2 threshold has been calculated within the framework of the diagonalization method.

Triple coincidence (e, 2egamma) measurements as a `perfect experiment' instrument for ionization-excitation studies

The potential of (e,2e) measurements to obtain perfect experiment information on the electron-impact ionization-excitation process is considered theoretically; calculations are presented for the reaction He(e,2e)He+.

NON-EQUILIBRIUM ENERGY-LOSS SPECTRA OF FAST IONS PROPAGATING THROUGH MATTER

Abstract A method of coupled integral equations for partial (charge selected) energy distributions of fast ions passing through matter under conditions of strong electron exchange with a medium is applied to the theoretical interpretation of recent experiments [H. Ogawa et al., Nucl. Instrum. Methods B 115 (1996) 66] on the evolution of the shape of energy-loss spectra of fast Li 2+ ions passing through thin carbon foils.

Inelastic and superelastic scattering of electrons by sodium: the role of the imaginary part of the optical potential in the DWBA analysis of the 3S-3P transition

The cross sections and correlation parameters of the 32S from or to 32P transitions induced by intermediate-energy electrons are calculated in the distorted-wave approximation with a phenomenological optical potential. The inclusion of the imaginary part of the potential improves the agreement with experiment.

Decay of collision-aligned autoionizing state 3s−1 4p 1P in argon

Abstract The triple differential cross section for excitation of the 3s−1 4p 1P autoionizing state in argon is calculated.

Electron-impact excitation of atomic autoionizing states from atoms excited by circular polarized laser

Abstract Electron-impact excitation of the doublet of autoionizing states 2p 5 3s3p 2 D 5/2 and 2p 5 3s3p 2 D 3/2 in a sodium atom from the laser-excited oriented (vector-polarized) state 2p 6 3p 2 P 3/2 is considered theoretically within the DWBA approach. A pronounced left–right asymmetry in the angular distrubution of the scattered electrons (the CPDAD effect) is predicted in the intermediate energy region.