Energy structure and transition rates in the Ne-like sequence from relativistic CI calculationsShow others and affiliations
2012 (English)In: Europhysics Conference Abstracts;36C, European Physical Society , 2012, p. 128-128Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]
Atomic data are important in astrophysical applications and transition rates can be used in
the determination of element abundances and plasma diagnostics. To provide for the extensive
data needs a number of general computer codes such as SUPERSTRUCTURE, CIV3, and
ATSP2K have been developed. As an alternative to these codes, which all rely on the Breit-Pauli
approximation, the fully relativistic GRASP2K code can be used. GRASP2K is based on
the multiconfiguration Dirac-Hartree-Fock method and implements a bi-orthogonal transformation
method that permits initial and final states in a transition array to be optimized separately,
which, in many cases, leads to more accurate values of the resulting rates. The GRASP2K
package also contains modules to compute diagonal and off-diagonal hyperfine interaction constants,
isotope shifts, Land´e gJ factors, and splittings of magnetic sub-state in intermediate and
strong magnetic fields. In this work, GRASP2K has been applied to provide highly accurate
spectroscopic data for ions in the Ne-like sequence between Mg III and Kr XXVII. Valence,
core-valence, and core-core correlation effects were accounted for through SD-MR expansions to
increasing sets of active orbitals. In Mg III, Al IV, Si V, P VI, S VII, and Ar IX, for which
experimental energies are known to high accuracy, the mean error in the calculated energies is
only 0.011%. For ions with no available experimental energy levels the calculated values should
be most valuable in various applications. The high accuracy of the calculated energies makes it
possible, in some cases, to to point out experimental values that are in error. Babushkin (length)
and Coulomb (velocity) forms of transition rates are computed and agree to within a few percent
for the majority of the allowed transitions. Computed lifetimes for states belonging to the 2p33s
and 2p53d configurations are in good agreement with values from beam-foil measurements as
well as from accurate MCHF Breit-Pauli calculations.
Place, publisher, year, edition, pages
European Physical Society , 2012. p. 128-128
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:mau:diva-16758Local ID: 14654OAI: oai:DiVA.org:mau-16758DiVA, id: diva2:1420272
Conference
European Group for Atomic Systems (EGAS), Gothenburg, Sweden (2012)
2020-03-302020-03-302022-09-19Bibliographically approved