arXiv subjects

L. V. Chernysheva

Publications and source records attributed to L. V. Chernysheva.

41 records · Page 3Linked to original sources

arXiv2007

On the angular distribution and spin polarization of the photoelectrons from semi-filled shell atoms

We present here the results of calculations of photoelectrons' angular anisotropy and spin-polarization parameters for a number of semi-filled shell atoms. We consider ionization of outer or in some cases next to the outer electrons in a number of elements from I, V, and VI groups of the Periodic Table. All calculations are performed with account of multi-electron correlations in the frame of the Spin Polarized version of the Random Phase Approximation with Exchange - SP RPAE. We consider the dipole angular distribution and spin polarization of photoelectrons from semi-filled subshells and from closed shells that are neighbors to the semi-filled shells. We have considered also angular anisotropy and spin-polarization of photoelectrons from some excited atoms that are formed by spin-flip of one of the outer electrons. To check the accuracy and consistency of the applied SP RPAE approach and to see the role of the nuclear charge variation only, we have calculated the dipole angular anisotropy and spin-polarization parameters of 3p - electrons in K and compare them to Ar and K+ that have the same configuration. Entirely, we have calculated the angular anisotropy and spin-polarization parameters for following subshells of atoms N (2p), P (3p), Ar (3p), K+(3p), K(3p), Cr(3p, 3d), Cr*(3d), Mn(3p, 3d), As(3d, 4p), Mo(4p, 4d), Mo*(4d), Tc(4p, 4d), Sb(4d, 5p), Eu(4f). The peculiarities of obtained parameters as function of photon frequencies are discussed, as well as some specific features of considered semi-filled shell objects.

physics.atom-ph↗

arXiv2007

Octupole Contributions to the Generalized Oscillator Strengths of Discrete Dipole Transitions in Noble Gases

The generalized oscillator strengths (GOS) of discrete excitations np-nd, both dipole (L=1) and octupole (L=3) are studied, the latter for the first time. We demonstrate that although the relevant transitions in the same atom are closely located in energy, the dependence of their GOS on the momentum transfer q squared, is remarkably different, so that the GOS corresponding to L=3 have at least one extra maximum as a function of q squared and dominate over those of the L=1, starting from about q=1.25$ atomic unit (a.u.). The calculations were performed in the one particle Hartree-Fock approximation and with account of many-electron correlations via the Random Phase Approximation with Exchange. The GOS are studied for values of q squared up to 30 a.u.

physics.atom-ph↗

arXiv2006

Non-dipole angular anisotropy parameters of semi-filled shell atoms

We present the results of calculations of outer shell non-dipole angular anisotropy parameters for semi-filled shell atoms in the Hartree-Fock (HF) one-electron approximation and with account of inter-electron correlations in the frame of the Spin Polarized Random Phase Approximation with Exchange (SP RPAE). We demonstrate for the first time that this characteristic of photoionization process is essentially sensitive to the fact whether the photoelectron has the same or opposite spin orientation to that of the semi-filled shell.

physics.atom-ph↗

arXiv2006

Photoionization of Xe 3d electrons in molecule Xe@C60: interplay of intra-doublet and confinement resonances

We demonstrate rather interesting manifestations of co-existence of resonance features in characteristics of the photoionization of 3d-electrons in Xe@C60. It is shown that the reflection of photoelectrons produced by the 3d Xe photoionization affects greatly partial photoionization cross-sections of and levels and respective angular anisotropy parameters, both dipole and non-dipole adding to all of them additional maximums and minimums. The calculations are performed treating the 3/2 and 5/2 electrons as electrons of different kinds with their spins "up" and "down". The effect of C60 shell is accounted for in the frame of the "orange" skin potential model.

physics.atom-ph↗

arXiv2003

Correlation structure in nondipole photoionization

The nondipole parameters that characterize the angular disribution of the photoelectrons from the 3d subshell of Cs are found to be altered qualitatively by the inclusion of correlation in the form of interchannel coupling between the $3d_{3/2}$ and $3d_{5/2}$ photoionization channels. A prominent characteristic maximum is predicted only in the parameters for $3d_{5/2}$ photoionization, while the effect for $3d_{3/2}$ is rather weak. The results are obtained within the framework of the Generalized Random Phase Approximation with Exchange (GRPAE), which in addition to the RPAE effects takes into account the rearrangement of all atomic electrons due to the creation of a 3d vacancy.

physics.atom-ph↗