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This study presents the investigation of magnetic dipole transition lines of W13+ ions in the wavelength range of 200–700 nm at a low-energy electron beam ion trap. Seventeen lines emitted from W13+ ions have been observed with three being reported experimentally for the first time. The atomic structure calculation and spectra simulation of W13+ ions have been carried out using the multiconfiguration Dirac–Hartree–Fock method combined with the relativistic configuration interaction approach and the collisional–radiative model, respectively. The theoretical calculations are in reasonable agreement with the experimental observations, and most of the observed lines have been identified. [ABSTRACT FROM AUTHOR]

Spectral lines of the magnetic-dipole transition between the 3 d 2 D 3 / 2 , 5 / 2 levels of K-like Kr17+, Zr21+, Nb22+, Mo23+, and Ru25+ ions were measured in a compact electron beam ion trap. By means of dedicated calibration methods, the transition wavelengths of Kr17+, Zr21+, and Mo23+ ions reduce uncertainties by at least one order of magnitude and the wavelengths of Nb22+ and Ru25+ ions are measured for the first time at a few ppm level. In addition, the fine-structure energy splittings were systematically calculated using the multiconfiguration Dirac–Hartree–Fock method combined with the relativistic configuration interaction approach. The contributions of the core-valence and core-core electron correlations, the Breit interaction and QED effect were discussed in detail. The results show that it is essential to include deep core-valence correlation of L -shell and core-core valence correlation of 3 p subshell to obtain an agreement better than 0.15% with existing experimental values. The calculation model can be performed to predict the wavelength within a high accuracy for a wide range of potassium-like ions. [ABSTRACT FROM AUTHOR]

The wavelengths and transition rates of W40+-W42+ ions within the range of 40–140 Å, have been calculated using the Flexible Atomic Code of the Dirac-Fock-Slater method with a central potential. We investigated the charge state distribution of W38+-W45+ ions at different temperatures by constructing an appropriate rate equation and demonstrate the importance of the dielectronic recombination process. Additionally, we simulated the emission spectra of W40+-W42+ ions in a Tokamak plasma environment using collisional-radiative modeling. Our findings demonstrate strong agreement with experimental results and other related theoretical investigations. Finally, we propose certain pairs of transition lines as diagnostic tools for plasma temperature and density, leveraging the correlation between line intensity ratio and electron temperature and density. [ABSTRACT FROM AUTHOR]

The properties and spectrum of the highly charged tungsten ions draw more and more attention, due to its potential application in the next generation fusion reactor. The transition wavelength and rate of the magnetic-dipole transition between the levels of the ground configuration of W53+ ion in the range of 10 − 20 nm were calculated by Dirac–Fock–Slater (DFS) method with a local central potential and Multi-Configuration Dirac-Hartree-Fock (MCDHF) method, respectively. The results are consistent with the previous EBIT experimental data and other theoretical data. A collisional-radiative model was constructed, and the spectrum of magnetic-dipole transition of W53+ ion observed on EBIT (Y. Ralchenko et al., Phys. Rev. A. 83 , 032517, 2011) was reproduced theoretically. Another two new transitions near the wavelength of 16.683 nm and 18.018 nm are also assigned to the M1 transition of W53+ ion. • The EBIT spectrum of W53+ ion was reproduced and analyzed by CRM with accurate atomic data. • The new M1 transition between the ground configuration of W53+ ions were assigned to the experimental spectrum. • The MCDHF transition wavelength was used instead of DFS results to get better agreement with the experiments. [ABSTRACT FROM AUTHOR]

This study presents both experimental and theoretical analysis of the 4 d 2 D 5 / 2 → 2 D 3 / 2 magnetic dipole transition in Rb-like ions. Spectral lines of Xe 17 + , La 20 + and Pr 22 + ions were recorded using an electron beam ion trap. The theoretical framework employed the fully relativistic Multi-configuration Dirac–Hartree–Fock method, accounting for the Breit interaction, QED effects and comprehensive core-valence correlation. An impressive correlation is observed between the theoretical and experimental findings. Notably, this study illustrates that the contribution of the core-valence correlation, especially concerning deep core subshells, is pivotal for the fine structure splittings. • Spectra of 4 d 2 D 5 / 2 → 2 D 3 / 2 transitions in Xe 17 + , La 20 + and Pr 22 + were observed at a compact EBIT. • An MCDHF FCV model with Breit and QED corrections predicts the energies within high accuracy. • Deep CV correlation effect is significant on the 4 d fine structure splitting in Rb-like ions. [ABSTRACT FROM AUTHOR]

• The experimental EUV spectrum from EAST Tokamak was analyzed by the collisional radiative modeling with highly accurate atomic data. • The population mechanism of the excited upper levels of W43+ ions was analyzed to explain the EBIT spectrum. • Some candidate diagnosis transition pairs were suggested according to the intensity dependence on the plasma temperature. The wavelength and transition rates of W43+-W45+ ions in the 40-140 Å region have been calculated by the relativistic configuration interaction method with the implementation of the Flexible Atomic Code to analyze the experimental spectrum from the EAST Tokamak. The result makes a reasonable agreement with the available EBIT experimental and other theoretical data. The population process of the W43+ ions were analyzed in detail. The synthetic spectrum from the collisional-radiative model of W43+-W45+ ions agreed with the Tokamak plasma spectrum. Some strong emission lines of the W43+-W45+ ions are identified and assigned in the present work. Finally, according to the dependence of the intensity ratio on the electron temperature, some transition pairs are proposed as the diagnosis lines. [ABSTRACT FROM AUTHOR]