A. G. Kochur

Term-dependent lifetime broadening effect on the 4d photoelectron spectrum of atomic thulium

The 4d photoelectron spectrum of free thulium atoms is measured and calculated in the single-configuration intermediate-coupling approximation considering multiplet splitting and lifetime broadening of the spectral components due to radiationless transitions following the 4d ionization. The individual natural widths of the 4d94f13 multiplet components are found to differ considerably, and the experimental profile of the spectrum can be reproduced theoretically only if this effect is taken into account.

Shake process probabilities for outer-shell electrons in atoms with Z⩽71

Relative probabilities of monopole shake processes are calculated in the sudden perturbation approximation for atoms with Z between 4 and 71. Most of the calculated data are presented compactly using a simple two-parameter interpolation formula for Z-dependences of shake probabilities per electron.

Monte Carlo simulation of cascade relaxation processes after 1s-photoionization of boron in the gas phase

The Monte Carlo technique is applied to simulate the processes of the cascade decay of boron atoms in the gas phase ionized by 20 Ryd photons. Processes of secondary excitation/ionization by the cascade-produced electrons and photons are considered. Final-ion-charge spectra, electron spectra and photon spectra are calculated at various atomic densities of the gaseous medium. The effect of the medium is found to be significant starting from atomic densities of about 1020 m−3. Inclusion of this effect is obligatory in the theoretical description of the decay cascades in dense samples.

DOUBLE-IONIZATION SATELLITES IN THE K-VV AUGER SPECTRA OF NEON-LIKE MOLECULES

The processes of monopole double ionization are investigated in the K-VV Auger spectra of the neon-like molecules (HF, H2O, NH3 , CH4 ). The spectra are calculated with simultaneous inclusion of multiplet splitting, final-state mixing and contributions of the ligands atomic orbitals to the molecular Auger transition amplitudes. The calculated relative integral intensities of the shake-off and shake-up spectator satellites are 18.2-20.5% of the total intensities of molecular Auger spectra. Taking the shake satellites into account allows us to assign some features of molecular Auger spectra.

Study of the electronic structure of polynuclear cobalt trimethylacetate complexes by Co3s and Co3p X-ray photoelectron spectroscopy

The electronic structure of mono-, hexa-, and nonanuclear cobalt trimethylacetate complexes was studied by XPS. The Co3s- and Co3p X-ray photoelectron spectra of the complexes were recorded. The Co3p spectrum of bivalent cobalt was calculated in the isolated-ion intermediate-coupling approximation. Spectrum analysis showed that the [Co(N-Phobsqdi)2(η′-N-Ph-opda)(OOCCMe3)] complex is a strong-field complex with Co(III) in the diamagnetic state; the [Co(dipy)2(OOCCMe3)2], [Co(dipyam)(OOCCMe3)2], and [Co9(μ3-OH)6(μ-OOCCMe3)12(OCMe2)4] are high-spin weak-field Co(II) complexes; and the [Co6(μ4-O)2(OOCCMe3)10(THF)4] complex contains both the Co(II) and Co(III) atoms. The energy position of major Co3s- and Co3p spectral maxima were found to be sensitive to the nature of the nearest environment of cobalt atoms. The data correlate well with X-ray crystallographic data.

Mn3s X-ray photoelectron spectra of polynuclear trimethylacetate complexes of manganese

The Mn3s X-ray photoelectron spectra of manganese at oms in mono-, bi-, tri-, and hexanuclear trimethylacetate Mn complexes and MnIICl2, MnIIIOOH, MnIVO2. ionic compounds were measured. The 3s spectra of the manganese atoms in MnII, MnIII, and MnIV valent states were calculated within the isolatedion approximation. The relationship between the characteristics of the Mn3s spectra and the magnetic moments of the manganese ions in the complexes is discussed.

Cascade-affected emission spectra of argon, krypton and xenon

Argon M1-M23, krypton N1-N23 and xenon O1-O23 emission spectra emitted during the cascading de-excitations of initial vacancies in the atomic inner subshells are calculated by straightforward construction of de-excitation trees in the configuration-averaged Hartree-Fock approximation. The spectra have complex spectator-vacancy satellite structures, reflecting the dynamics of the de-excitation processes.

The relative role of shake-up and shake-off processes in additional monopole excitation of L and M electrons due to inner atomic shell ionization

The probabilities of additional monopole excitation (shake-up) and ejection (shake-off) processes for electrons of the L and M shells upon K and L ionization for atoms with 3 ≤ Z ≤ 38 are calculated in the sudden perturbation approximation. With increasing atomic number, the portion of the nl-electron shake-offs in the total probability of monopole shake-up/shake-off processes increases from several percent in the beginning of the nl subshell population to above 50% after its filling. Within one shell, the shake-off processes are relatively more probable for electrons with smaller orbital quantum numbers.

Probabilities of multiple shake processes in sudden approximation

The probabilities of single, double, triple and quadruple shake processes upon inner-shell K-, L-, M- and N-ionization are calculated in the sudden perturbation approximation for the atoms with 3 ≤ Z ≤ 55. Multiple shake processes make 10 to 30% of all the shake processes involving a given nl outer subshell depending on the orbital quantum number l, on the subshell occupation, and on the initial inner-shell vacancy.

Calculation of Xei+ photoion yields in coincidence with energy-selected M45NN Auger electrons

A theoretical model to calculate the photoion yields registered in coincidence with fixed-energy Auger electrons is developed. The intermediate-coupling approximation is used to calculate the term structure of the two-hole states reached by Auger transitions, and the branching ratios of their further Auger, Coster–Kronig and super Coster–Kronig decays into the three-hole states. The remaining parts of the cascading decay de-excitation trees are simulated in configuration-average approximation for branching ratios and transition energies. Our calculation allowed us to explain the recent M45NN Auger-electron–photoion coincidence experiment upon M45 photoionization of Xe.