Atomic Data and Nuclear Data Tables最新文献

Using wave number calibrated Fourier transform spectra, ranging from the IR to the UV regions, we determined with high accuracy the energies of the levels of the first ion of Niobium. In order to increase the accuracy of the center of gravity wave numbers of the observed spectral lines, the hyperfine structure was taken into account. For this purpose, the magnetic dipole hyperfine constants $A$ were determined for all involved levels. All but one of the previously known levels were included in the calculation. This level (at 91 493 cm⁻¹) is considered to be non-existent. From the experimental center of gravity wave numbers of 1121 lines we deduced the energy values of 184 levels of even parity and 164 levels of odd parity in a global fit. A comparison between our results and all previously available literature values is provided.

Argon is being considered as an injected impurity to mitigate damage to divertors of DEMO caused by excessive heat flux. For a comprehensive understanding of Ar plasma, carefully evaluated atomic data are required. In this study, the electron-impact ionization cross-sections and rate coefficients for all atomic ions in the argon isonuclear sequence are calculated using the level-to-level distorted wave approximation. The calculated cross-sections and rate coefficients are compared with experimental data and other theoretical calculations. The calculated values are consistent with results reported in the literature, with differences not exceeding 20%. We fit the calculated cross-sections using an empirical formula. Additionally, we combine our ionization rate coefficients with the dielectronic- and radiative-recombination rate coefficients from other studies to determine the ionization balance. The obtained data are expected to be useful for plasma modelling involving argon impurities.

The mass table in the deformed relativistic Hartree–Bogoliubov theory in continuum (DRHBc) with the PC-PK1 density functional has been established for even-$Z$ nuclei with $8\le Z\le 120$, extended from the previous work for even–even nuclei (Zhang et al. (DRHBc mass table collaboration), At. Data Nucl. Data Tables 144, 101488 (2022)). The calculated binding energies, two-nucleon and one-neutron separation energies, root-mean-square (rms) radii of neutron, proton, matter, and charge distributions, quadrupole deformations, and neutron and proton Fermi surfaces are tabulated and compared with available experimental data. A total of 4829 even-$Z$ nuclei are predicted to be bound, with an rms deviation of 1.433 MeV from the 1244 mass data. Good agreement with the available experimental odd–even mass differences, $\alpha$ decay energies, and charge radii is also achieved. The description accuracy for nuclear masses and nucleon separation energies as well as the prediction for drip lines is compared with the results obtained from other relativistic and nonrelativistic density functional. The comparison shows that the DRHBc theory with PC-PK1 provides an excellent microscopic description for the masses of even-$Z$ nuclei. The systematics of the nucleon separation energies, odd–even mass differences, pairing energies, two-nucleon gaps, $\alpha$ decay energies, rms radii, quadrupole deformations, potential energy curves, neutron density distributions, and neutron mean-field potentials are discussed.

Large-scale relativistic multiconfiguration Dirac–Fock calculations of energy levels and lifetimes of the 206 states arising from the 3s²3p, 3p³, 3s3p3d, 3p3d², 3s²4p, 3s²4f, 3s3p², 3s²3d, 3s3d², 3s²4d, 3s²4s, 3s3p4s, 3s3p4d, 3p²3d, 3d³, and 3s3p4p configurations of Zr XXVIII, Nb XXIX, and Tc XXXI of tokamak interest are carried out. The active space approximation is employed for the calculations. To obtain accurate and convergent results, the calculations take into account the valence and core-valence correlations within the n $=$ 9 complex, as well as the Breit interaction, self-energy corrections, and vacuum polarization corrections. Detailed information regarding the decay properties of these ions is provided, including the transition wavelengths, line strengths, and radiative transition rates for various types (electric dipole, electric quadrupole, magnetic dipole, and magnetic quadrupole transitions) of transitions among the levels of the aforementioned configurations. The uncertainties of each dipole transition are evaluated. The present data sets are compared to previous results and a good agreement is observed, which is valuable for emission line identification and fusion modeling, especially in situations where experimental data are scarce.

Theoretical photoionization cross-sections and angular distribution parameters for valence and subvalence shells of 3d-elements from Sc to Zn are calculated with account for intrachannel and interchannel interactions for the energy region from threshold up to 400 eV. Many-electron effects were accounted for within the framework of RPAE (random phase approximation with exchange) method, which is extended for average terms of unfilled shells. Calculations demonstrate a decrease of σ(3 s) by approximately 25 %- 30 % for photon energies up to 24 Ry. and significant increase of σ(4s) for photon energies up tp 4 Ry and also a small decrease σ(3p) relative to the HFS results of Yeh and Lindau, whereas the influence of correlations on σ(3d) is negligible

The structural properties of doubly excited ${}^{1,3}{F}^e$ metastable-bound and resonance states of neutral helium atom under exponentially screened Coulomb potential are studied using explicitly correlated multi-exponent Hylleraas type basis set. Precise energy eigenvalues of $2pnf\left({}^{1,3}{F}^e\right)$ states $\left(n=4-15\right)$ are estimated in the framework of Ritz variational principle. Stabilization method has been employed to calculate the resonance parameters (energy and width) of ${}^{1,3}{F}^e$ states below $H{e}^{+}\left(3p\right)$ and $H{e}^{+}\left(4p\right)$ thresholds for different screening conditions. The resonance parameters above $H{e}^{+}\left(3p\right)$ threshold under screened Coulomb environment are reported for the first time in literature. Furthermore, pioneering calculations for the variation of structural properties such as one- and two-particle moments and inter-electronic angles are carried out for both metastable-bound and resonance ${}^{1,3}{F}^e$ states of He atom under screened Coulomb potential. The present results may serve as benchmark for future references.

Multiconfiguration Dirac–Hartree–Fock (MCDHF) and relativistic configuration interaction (RCI) methods are utilized for theoretical calculations of energy levels, wavelengths, line strengths, absorption oscillator strengths, and transition probabilities in 3s²-3s4p, 3s3p-3s4s, 3s3p-3s4d, 3s3p-3p4p, 3s3d-3s4f, 3p²-3p4s, 3p²-3p4d, and 3p3d-3p4f transitions in Mg-like ions with $15\le Z\le 30$. The calculations of energies account for Breit interaction and quantum electrodynamics (QED) contributions. The active space approximation is employed for the calculations, and energy converges when the active orbital set is increased to $n$ = 7. The calculated lowest 78 levels including valence and core–valence correlations in Mg-like ions with Z=15–30 show good agreement with experiment results and other calculations. The relative difference between calculated wavelengths and experiment values exhibits a decreasing trend as the atomic numbers increase, and the difference is better than 1% for a majority of transitions. To evaluate the accuracy of the wave functions and transition parameters, the quantity $dT$ is analyzed within 0.1 for most strong transitions. The transition probabilities are compared with other theoretical values to analyze with line strength S. Such calculations may provide valuable data for the experimental study of plasma diagnostics and modeling as there are others.

Energies, wavelengths and transition rates in Mn VI and Cr V have been calculated using the multiconfiguration Dirac-Hartree–Fock (MCDHF) and relativistic configuration interaction (RCI) methods. The present calculations have been compared with the available data from the NIST ASD and other calculations to evaluate the accuracy of the present calculations. The calculated 25 lowest energy levels have good agreement with the data from the NIST ASD and should provide missing data, especially for levels of the $3p^{5}3d^3$ configuration in the NIST ASD. The calculated $E1$ transitions of the type $3p^{6}3d^2$ - $3p^{6}3d4p$ and $E2$ transitions of the types $3p^{6}3d^2$ - $3p^{6}3d4s$ and $3p^{6}3d^2$ - $3p^{6}3d^3$ are in excellent agreement with the NIST ASD. The consistence between present calculated $E2$ and $M1$ transitions within the $3d^2$ configuration are worse with the NIST ASD. The data obtained are expected to be useful for nebula and supernovae analyses.