Radiative Transition Wavelengths Research Articles

Theoretical level energies and transition data for 4p[formula omitted]4d[formula omitted], 4p[formula omitted]4d[formula omitted] and 4p[formula omitted]4d[formula omitted]4f configurations of W[formula omitted] ion

The ab initio quasirelativistic approach developed specifically for the calculation of spectral parameters of highly charged ions has been used to determine transition data for the Mo-like tungsten ion W32+. The configuration interaction method is utilized to include electron correlation effects. The relativistic effects are taken into account in the Breit–Pauli approximation. Level energies, radiative lifetimes τ, Landé g-factors are determined for the ground configuration 4p64d6 and two excited configurations 4p54d7 and 4p64d54f. The radiative transition wavelengths λ, emission transition probabilities A, weighted oscillator strengths gf, and transition line strengths S for the electric dipole, electric quadrupole, electric octupole, magnetic dipole, and magnetic quadrupole transitions among the fine-structure levels of these configurations are produced. The uncertainties of computed spectroscopic parameters are evaluated.

Calculations of term energies, radiative transition wavelengths and Auger electron energies for resonances of F4+

In this work, the saddle-point variation combined with complex-rotation methods are used to calculate term energies, radiative transition wavelengths and Auger transition energies of the 1s2s22p2 (2S, 2P, 2D, 4P), 1s2s22p3p (2S, 2P, 2D), 1s2s2p3 (2,4S°, 2,4P°, 2,4D°), and 1s2p4 (2S, 2P, 2D, 4P) resonances for F4+. The present term energies, radiative rates, radiative transition wavelengths, Auger rates and corresponding transition energies agree well with the multiconfiguration Dirac-Fock calculation results listed in the literature. Other transition data in this work are expected to offer reference values for future studies.

Theoretical level energies and transition data for 4p64d8, 4p54d9 and 4p64d74f configurations of W[formula omitted] ion

The ab initio quasirelativistic approach developed specifically for the calculation of spectral parameters of highly charged ions was used to derive transition data for the Ru-like tungsten ion W30+. The configuration interaction method was applied to include electron correlation effects. The relativistic effects were taken into account in the Breit–Pauli approximation. The level energies, radiative lifetimes τ, Landé g-factors were determined for the ground configuration 4p64d8 and two excited configurations 4p54d9 and 4p64d74f. The radiative transition wavelengths λ and emission transition probabilities A for the electric dipole, electric quadrupole, electric octupole, magnetic dipole, and magnetic quadrupole transitions among the levels of these configurations were generated.

Theoretical level energies and transition data for ion W[formula omitted

The quasirelativistic approach was used to derive transition data for the Rh-like W29+ tungsten ion. The quasirelativistic approach was developed specifically for the calculation of spectral parameters of highly charged ions. The relativistic effects were taken into account in the Breit–Pauli approximation. The configuration interaction method was applied to include electron correlation effects. The ground W29+ configuration 4p64d9 and two odd-parity configurations 4p54d10 and 4p64d84f were investigated. Different sets of configuration-interaction extensions were applied for assessment of calculation accuracy. The level energies, radiative lifetimes τ, and Landé g-factors were determined for levels of the excited configurations 4p54d10 and 4p64d84f and the ground configuration 4p64d9. The radiative transition wavelengths λ and emission transition probabilities A for the electric and magnetic transitions of high multipole order among the levels of these configurations were produced. The uncertainties of computed spectroscopic parameters were evaluated. Such a complete and inclusive data set for the levels of two excited configurations and their radiative properties in W29+ is reported for the first time.

Theoretical level energies and transition data for ion W[formula omitted

The ab initio quasirelativistic approach was used to derive transition data for Pd-like tungsten W28+ ion. This approach was developed specifically for the calculation of spectral parameters for highly charged ions. The relativistic effects were taken into account in the Breit–Pauli approximation. The configuration interaction method was applied to include electron correlation effects. The ground configuration 4p64d10 and the lowest excited 4p64d94f were considered. The calculations for W28+ were performed with different sets of interacting configurations in order to evaluate reliability and accuracy of produced results. Level energies, radiative lifetimes τ, Landé g-factors were determined for the excited configuration 4p64d94f of W28+ levels. The radiative transition wavelengths λ and emission transition probabilities A for the electric and magnetic transitions of various multipole order (up to E5 and M4) among the levels of these two configurations were produced. The uncertainties of computed spectroscopic parameters were evaluated.

Plasma environment effects on K lines of astrophysical interest

Aims. In the context of black-hole accretion disks, the main goal of the present study is to estimate the plasma environment effects on the atomic structure and radiative parameters associated with the K-vacancy states in ions of the oxygen isonuclear sequence. Methods. We used a time-averaged Debye–Hückel potential for both the electron–nucleus and the electron–electron interactions implemented in the fully relativistic multiconfiguration Dirac–Fock (MCDF) method. Results. Modified ionization potentials, K thresholds, Auger widths, and radiative transition wavelengths and rates are reported for O I–O VII in plasma environments with electron temperature and density ranges 105−107 K and 1018−1022 cm−3.

Хвильові і осциляторні сильні сторони Li-подібних багатозарядних іонів в рамках теорії відносного збудження багатьох тіл

The relativistic many-body perturbation theory with the optimized Dirac-Kohn-Sham zeroth approximation is applied to calculation of the radiative transitions wavelengths and oscillator strengths for some Li-like multicharged ions. The relativistic, exchange-correlation and other corrections are accurately taken into account. The optimized relativistic orbital basis set is generated in the optimal many-body perturbation theory approximation with fulfilment of the gauge invariance principle. An accurate treatment of the QED perturbation theory fourth order (a second order of the atomic perturbation theory) Feynman diagrams (whose contribution into the energy shift imaginary part (radiation width) for the multi-electron atoms accounts for multi-body correlation effects) is performed. The obtained data on the radiative transition wavelengths and oscillator strengths for some transition in spectra of the Li-like multicharged ions are analyzed and compared with alternative theoretical and experimental results.

Theoretical level energies and transition data for 4p64d5, 4p54d6 and 4p64d44f configurations of W33+ ion

The ab initio quasirelativistic approach developed specifically for the calculation of spectral parameters of highly charged ions was used to derive transition data for the Nb-like tungsten ion W33+. The configuration interaction method was applied to include electron correlation effects. The relativistic effects were taken into account in the Breit–Pauli approximation. The level energies, radiative lifetimes τ, Landé g-factors were determined for the ground configuration 4p64d5 and two excited configurations 4p54d6 and 4p64d44f. The radiative transition wavelengths λ and emission transition probabilities A for the electric dipole, electric quadrupole, electric octupole, magnetic dipole, and magnetic quadrupole transitions among the levels of these configurations were produced. The uncertainties of computed spectroscopic parameters were evaluated.

Radiative transitions for three lowest configurations of tungsten ions W38+–W43+

The ab initio quasirelativistic approximation was used to derive transition data for the multicharged tungsten ions W38+–W43+ with an open 4p shell. The configuration interaction method with transformed radial orbitals was applied to include electron correlation effects. The relativistic effects were taken into account in the Breit–Pauli approximation for the quasirelativistic Hartree–Fock radial orbitals. The level energies E, radiative lifetimes τ, and Landé g-factors were calculated for the 4s24pN, 4s24pN–14d, and 4s4pN+1 configurations of six tungsten ions. The radiative transition wavelengths λ, spontaneous emission transition probabilities A and their uncertainties for the electric dipole, electric quadrupole, electric octupole, magnetic dipole and magnetic quadrupole transitions among the levels of these configurations are presented.

Theoretical level energies and transition data for 4p64d4, 4p64d34f and 4p54d5 configurations of W34+ ion

The ab initio quasirelativistic approach developed specifically for the calculation of spectral parameters of highly charged ions was used to derive transition data for the tungsten ion W34+. The configuration interaction method was applied to include electron correlation effects. The relativistic effects were taken into account in the Breit–Pauli approximation. The level energies, radiative lifetimes τ, Landé g-factors are determined for the ground configuration 4p64d4 and two excited configurations 4p64d34f and 4p54d5. The radiative transition wavelengths λ and emission transition probabilities A for the electric dipole, electric quadrupole, electric octupole, magnetic dipole, and magnetic quadrupole transitions among the levels of these configurations are produced.

Theoretical investigation of spectroscopic properties of W26+ in EBIT plasma

Energy levels, radiative transition wavelengths and probabilities have been studied for the ion using multiconfiguration Dirac–Fock and Dirac–Fock–Slater methods. Corona and collisional-radiative models have been applied to determine lines and corresponding configurations in a low-density electron beam ion trap (EBIT) plasma. Correlation effects for the 4f2, , (), () configurations have been estimated by presenting configuration interaction strengths. It was determined that correlation effects are important for the transitions corresponding to weak electric octupole transitions in a single-configuration approach. Correlation effects influence the transitions by increasing transition probabilities by an order of magnitude. Identification of some lines observed in fusion plasma has been proposed. Spectra modeling shows strong increase of lines originating from the transitions. Other transitions from the 10–30 nm region can be of interest for the EBIT plasma.

Inner-shell photoexcitation of Fe xv and Fe xvi

The configuration-interaction method as implemented in the computer code CIV3 is used to determine energy levels, electric dipole radiative transition wavelengths, oscillator strengths and transition probabilities for inner-shell excitation of transitions in Fe XV and Fe XVI. Specif

Large ground-to-first-excited-state transition energy separation for InAs quantum dots emitting at 1.3 μm

By capping InAs quantum dots (QDs) with a thin intermediate layer of InAlAs instead of GaAs, the radiative transition wavelengths are redshifted. Surface morphology studies confirm that the redshift is due to a better preserved QD height as compared with capping by GaAs only. In contrast, the energy levels are blueshifted when using AlGaAs instead of GaAs as the barrier material. In both cases, the energy separation between the ground and the first-excited state increases significantly. Combining these approaches, we demonstrate InAs QDs with a record transition energy separation of 108 meV and ground-state emission at 1.3 μm.