Multiconfigurational Dirac–Fock atomic structure calculations for Cl-like tungsten

Abstract

Energy levels, lifetimes, and wavefunction compositions have been calculated for all levels of odd parity 3s23p5 ground configuration as well as 3s3p6 and 3s23p43d even parity excited configurations in highly charged Cl-like tungsten ion. Transition probabilities, oscillator strengths, and line strengths for E1, E2, M1, and M2 transitions have been obtained using the fully relativistic multiconfiguration Dirac–Fock (MCDF) approach including the correlations within the n = 3 complex, some n = 3 → n = 4 single and double excitations and Breit and quantum electrodynamics effects. For comparison from our calculated energy levels, we have also calculated the energy levels by using the fully relativistic flexible atomic code (FAC). The validity of the method is assessed by comparison with previously published experimental and theoretical data. The excellent agreement observed between our calculated results and those obtained using different approaches confirm the accuracy of our results. Additionally, we have predicted some new atomic data for W57+ that are not available so far and may be important for plasma diagnostic analysis in fusion plasma.

Radiative rates for E1, E2, M1, and M2 transitions among the 3s23p5, 3s3p6, and 3s23p43d configurations of Cl-like W LVIII

“…With the same amount of CI as included in GRASP1 and GRASP2, the energy levels from FAC are comparable as listed in Table 2. This has also been shown by Mohan et al [8] in their Table 2, and hence those results are not included in the present Table 2. However, we have performed four additional calculations with FAC, with increasing CI.…”

“…In Table 2 we compare our calculated energies for 31 levels of the 3s 2 3p 5 , 3s3p 6 , and 3s 2 3p 4 3d configurations with those of Mohan et al [8]. Laboratory measurements have been compiled by Kramida [22] and the NIST (National Institute of Standards and Technology) team [21], which are also included in the table.…”

“…In particular, Cl-like ions are very complicated and CI is highly important, as demonstrated by Aggarwal and Keenan for Ti VI [15], Cr VIII [16], Fe X [17], and Co XI [18]. These are comparatively light ions but W LVIII is no exception, and therefore Mohan et al [8] have included CI among 15 configurations (GRASP1), namely, 3s 2 3p 5 , 3s3p 6 , 3s 2 3p 4 3d, 3s 2 3p 4 4ℓ, 3s3p 5 3d, 3s 2 3p 3 3d 2 , 3s3p 4 3d 2 , 3p 6 3d, 3s 2 3p 2 3d 3 , 3p 5 3d 2 , 3s 2 3p 3 4d 2 , and 3s 2 3p 3 4f 2 . However, inclusion of this limited CI is not sufficient for an accurate determination of energy levels and radiative rates (A-values).…”

“…For our calculations we have employed the same GRASP code as adopted by Mohan et al [8]. Additionally, we have used the option of extended average level, in which a weighted (proportional to 2j + 1) trace of the Hamiltonian matrix is minimised.…”

“…In a recent paper, Mohan et al [8] have reported results for energy levels, oscillator strengths, radiative rates, line strengths, and lifetimes for Cl-like W LVIII. For the calculations, they adopted the widely used and readily available general-purpose relativistic atomic structure package (GRASP) code.…”