Dirac R-matrix calculations of photoionization cross sections of Ni XII and atomic structure data of Ni XIII

Abstract

We performed R-matrix calculations for photoionization cross sections of the two ground state configuration 3s 2 3p 5 ( 2 P o 3/2,1/2 ) levels and 12 excited states of Ni XII using relativistic Dirac Atomic R-matrix Codes (DARC) across the photon energy range between the ionizations thresholds of the corresponding states and well above the thresholds of the last level of the Ni XIII target ion. Generally, a good agreement is obtained between our results and the earlier theoretical photoionization cross sections. Moreover, we have used two independent fully relativistic GRASP and FAC codes to calculate fine-structure energy levels, wavelengths, oscillator strengths, transitions rates among the lowest 48 levels belonging to the configuration (3s 2 3p 4 , 3s3p 5 , 3p 6 , 3s 2 3p 3 3d) in Ni XIII. Additionally, radiative lifetimes of all the excited states of Ni XIII are presented. Our results of the atomic structure of Ni XIII show good agreement with other theoretical and experimental results available in the literature. A good agreement is found between our calculated lifetimes and the experimental ones. Our present results are useful for plasma diagnostic of fusion and astrophysical plasmas.

Theoretical study of the hyperfine interaction constants, Landé g-factors, and electric quadrupole moments for the low-lying states of the 61Ni q+ (q = 11,12,14, and 15) ions

“…[17] In addition, theoretical researches on nickel HCIs mostly focused on transition properties, which are relevant to the emission from the solar, astrophysical, and laboratory plasmas. [18][19][20][21] However, in order to analyze the precision spectra and realize HCIs optical clock, calculations on the atomic parameters, such as the hyperfine interaction constants, Landé g-factors, and electric quadrupole moment of the clock states, are necessary.…”

Relativistic R-matrix calculations for L-shell photoionization cross sections of C II

“…[1,2] Besides its fundamental significance, the PI cross section is also of vital importance as applied data in atmospheric physics, astrophysics, and plasma and tokomak researches. [3][4][5] Much theoretical and experimental effort has been devoted for over three decades to the study of PI cross sections. Among these theoretical researches, the most comprehensive studies have been carried out for a large number of relatively light atoms and ions of astrophysical relevance by using the close-coupling R-matrix method in the frame work of the Opacity Project, [6,7] the Iron, [8] and the RmaX projects.…”