Near-threshold Electron-impact Excitation of Multiply-charged Be-like Ions

Relativistic Energy Approach and Many-Body Perturbation Theory to Computing Electron-Collision Cross-Sections of Complex Multielectron Ions

“…It should be mentioned the currently widespread and widely used R-matrix method and its various promising modifications, as well as a generalization of the wellknown Dirac-Fock method to the case of taking into account multipolarity in the corresponding operators (see, e.g. , [1][2][3][4][5][6][7]). It should be noted that, depending on the perturbation theory (PT) basis used, different versions of the R-matrix method received the corresponding names.…”

“…As numerous applications of the R-matrix method have shown, it has certain advantages in terms of accuracy and consistency over such popular approaches as the first-order PT method, as well as the distorted wave approximation taking into account configuration interaction ( CI-DWBA); --approximation of distorted waves using the HF basis (HF-DWBA), finally, the relativistic approximation of distorted waves with a 1-configuration and multi-configuration wave function of the ground state (SCGS-RDWA, MCGS-RDWA, etc.). Improved models have also appeared in theories of the coupled-channel (VC) type VCDWA (Variational Continuum Distorted Wave), for example, a modification of the Vraun-Scroters type and others (see [1][2][3][4][5]). Various cluster methods have also been widely used (see in more details [1][2][3]14,15]).…”

Electron-Collisional Spectroscopy of Atoms and Ions: Advanced Energy Approach

“…Electron-collisional spectroscopy of atoms and multicharged ions is one of the most fast developing branches of modern atomic spectroscopy. The properties of laboratory and astrophysical plasmas have drawn considerable attention over the last decades [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. It is known that multicharged ions play an important role in the diagnostics of a wide variety of plasmas.…”

“…It should be mentioned the currently widespread and widely used Rmatrix method and its various promising modifications, as well as a generalization of the wellknown Dirac-Fock method to the case of taking into account multipolarity in the corresponding operators (see, e.g. , [1][2][3][4][5][6][7]). It should be noted that, depending on the perturbation theory (PT) basis used, different versions of the R-matrix method received the corresponding names.…”

SPECTROSCOPY OF MULTICHARGED IONS IN PLASMAS: OSCILLATOR STRENGTHS OF Be-LIKE ION Fe

“…Spectroscopy of multicharged ions in a plasmas is one of the most fast developing branches of modern atomic spectroscopy. Let us remind that a great interest to studying radiation and collision processes parameters in a plasmas is connected with importance of these data for correct description of parameters characteristics for plasma in thermonuclear (tokamak) reactors, searching new mediums for X-ray range lasers [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In many papers the calculations of various atomic systems embedded in Debye plasmas have been performed ( [13][14][15][16]).…”