Spectroscopy of diagnostically important magnetic-dipole lines in highly charged3dnions of tungsten

Abstract

An electron-beam ion trap (EBIT) is used to measure extreme ultraviolet spectra between 10 and 25 nm from highly charged ions of tungsten with an open 3d shell (W XLVIII through W LVI ). We found that almost all strong lines are due to the forbidden magnetic-dipole (M1) transitions within 3d n ground configurations. A total of 37 previously unknown spectral lines are identified using detailed collisional-radiative (CR) modeling of the EBIT spectra. A level-merging scheme for compactification of rate equations is described. The CR simulations for Maxwellian plasmas show that several line ratios involving these M1 lines can be used to reliably diagnose temperature and density in hot fusion devices.

E1, M1, E2 transition energies and probabilities of W54+ions

“…Notation a(b) for transition probabilities A ij means a × 10 4SD, 5SD(5s-5d), 5SD and 6SD(6s-6d) are given in Table 1. "Other" represents the results from EBIT experiments or other theoretical work, such as RMBPT, MCDF and RCI method [7][8][9][10]. For the M1 transitions, the calculated wavelengths and probabilities are converged with the increase of AS and are in reasonable agreement with available experimental data.…”

“…U. I. Safronova et al calculated the magnetic dipole (M1) and electric quadrupole (E2) transitions between the multiplets of the ground state configuration ([Ne]3s 2 3p 6 3d 2 ) of W 54+ by using the relativistic many-body perturbation theory (RMBPT) [7]. Y. Ralchenko et al observed the M1 lines from 3d n (n=1-9) ground state fine structure multiplets of tungsten ions with electron-beam ion trap (EBIT) and they employed a non-Maxwellian collisionalradiative model to analyze the observed spectrum [8]. P. Quinet calculated the forbidden transitions within the 3p k (k=1-5) and 3d n (n=1-9) ground state configuration multiplets of highly charged tungsten ions (W 47+ −W 61+ ) by multi-configuration Dirac-Fock (MCDF) method taking into account the correlations between a restricted number of configurations [9].…”

Correlation, Breit and Quantum Electrodynamics effects on energy level and transition properties of W54+ ion

“…The 9 energy levels (in eV) including correlation, Breit interaction and QED effects (C+B+Q) of the ground configuration 3p 6 3d 2 of W 54+ ion were presented in Table 2 to investigate the contribution from the Breit and QED effects. The other available theoretical and experimental results were also listed for comparison [4,5,6,7]. The notation "C+B+Q" and "Coulomb" in the 4 th and 2 th columns of the table represent the results with and without Breit and QED effects which calculated in n=5(5s-5d) model [5] b From P. Quinet by MCDF method [6] c From U. I. Safronova and A. S. Safronova by RMBPT method [4] d From X. L. Guo et al by RMBPT method [7] e From X. L. Guo et al by RCI method [7] and regarding 3s,3p orbital as core and VV+CV+CC correlations were taken into account.…”

“…In recent several decades, several theoretical and experimental work have been performed on the energy level and the E1, E2, M1 transitions properties of W 54+ ion [2,3,4,5,6,7,8,9]. U. I. Safronova et al calculated 9 fine a Email:dingxb@nwnu.edu.cn structure levels belonging to the ground state configuration [Ne]3s 2 3p 6 3d 2 of W 54 ions, and the M1 and E2 transitions between these levels also have been studied by using the relativistic many-body perturbation theory (RMBPT) [4].…”

“…Furthermore, X. L. Guo et al calculated the energy, transition wavelength and probability for forbidden transition within the 3d k ground configuration of highly charged Hf, Ta, Au and W ions by RMBPT and the relativistic configuration-interaction (RCI) method [7]. Y. Ralchenko et al observed the M1 spectrum from 3d n (n=1-9) ground state fine structure multiplets of tungsten ions with electron-beam ion trap (EBIT) and a non-Maxwellian collisional-radiative model was used to analyze the observed spectrum [5]. The configuration interaction among n=3 complex and the single excitation up to n=5 was included in their calculation.…”