The multi-configurational Dirac–Hartree–Fock method has been used to examine the electron correlation effect on wavelengths and transition rates for L→K transitions occurring in He- Li-like nickel ions. collisional-radiative modelling approach simulate X-ray spectra, a 1.585–1.620 Å wavelength range, originating from He-like ions their dielectronic Li-, Be-, B-like satellites various temperature values 2 keV 8 range. presented results may be useful improving plasma diagnostics based spectra.

We propose a novel approach for the theoretical analysis of photoinduced high-resolution K(h)α(1,2) x-ray hypersatellite spectra, which allows us to obtain reliable values lifetimes doubly K-shell ionized states and fundamental information about relative role double photoionization (DPI) mechanisms. It is demonstrated first time that natural line broadening observed selected metal atoms with 20 ≤ Z 30 can be well reproduced quantitatively by taking into account influences open-shell valence...

The x-ray transitions in Cu- and Ni-like tungsten ions the 5.19--5.26 \AA{} wavelength range that are relevant as a high-temperature tokamak diagnostic, particular for JET ITER-like wall configuration, have been studied. Tungsten spectra were measured at upgraded Shanghai- Electron Beam Ion Trap operated with electron-beam energies from 3.16 to 4.55 keV. High-resolution measurements performed by means of flat Si 111 crystal spectrometer equipped CCD camera. experimental wavelengths...

Several issues concerning Breit correction to electron-electron interaction in many-electron systems, which are important precise atomic and molecular calculations, presented. At first, perturbative versus self-consistent calculations of were studied selected cases. Second, the Z-dependence contribution per subshell is shown, based on values calculated for atoms with 30 ≤ Z 118. Third, relations between magnetic retardation parts analyzed. Finally, Gaunt Kr, Xe, Rn noble gas its...

Several issues, concerning QED corrections, that are important in precise atomic calculations presented. The leading self-energy and vacuum polarization, to the orbital energy for selected atoms with 30 ≤ Z 118 have been calculated. sum of Breit contributions is analyzed. It has found ns subshells comparative size, but np nd contribution takes a major part QED+Breit sum. also, ratio almost independent Z. Z-dependence Breit+QED per subshell shown. fitting coefficients may be used estimate...

We show here results of four-component calculations nuclear magnetic resonance σ for atoms with 10 ≤ Z 86 and their ions, within the polarization propagator formalism at its random phase level approach, first estimation quantum electrodynamic (QED) effects Breit interactions those atomic systems by using two theoretical effective models. also QED corrections to σ(X) in simple diatomic HX X2 (X = Br, I, At) molecules. found that dependence bound-state many-electron is proportional Z5, which...

NMR shielding constants for He- and Be-like atomic systems of Ne, Ar, Kr, Xe, Rn have been calculated at the random-phase-approximation level approach, including an estimation QED corrections within polarization propagator formalism. We show that effects enhance electron correlation when $Z$ becomes heavier, which happens with relativistic effects, also become smaller going from more to less ionized systems. studied two- four-electron Then such studies could easily be generalized other...

The results of relativistic calculations nuclear magnetic resonance shielding tensors (σ) for the thallium monocation (Tl+), hydride (TlH), and halides (TlF, TlCl, TlBr, TlI, TlAt) are presented as obtained within a four-component polarization propagator formalism two-component linear response approach zeroth-order regular approximation. In addition to detailed analysis effects performed in this work, some quantum electrodynamical (QED) on those shieldings other small contributions...

We present theoretical predictions for iridium Kα1,2, Kβ1,3 and Kβ2 energy shifts as a function of outer-shell stripping, evaluated using the multiconfiguration Dirac–Fock method including Breit interaction QED corrections. The are consistent with K-lines emitted by plasma made in plasma-filled rod pinch, potentially relevant to diagnostics high-energy density laser-produced plasmas studied connection National Ignition Facility.

The indirect spin-spin coupling tensor, J, between mercury nuclei in systems containing this element can be of the order a few kHz and one largest measured. We analyzed physics behind electronic mechanisms that contribute to one- two-bond couplings nJHg-Hg (n = 1, 2). For doing so, we performed calculations for J-couplings ionized X22+ X32+ linear molecules (X Zn, Cd, Hg) within polarization propagator theory using random phase approximation pure zeroth-order with Dirac-Hartree-Fock...

The $4d\ensuremath{\rightarrow}3p$ x-ray transitions in Cu- and Ni-like tungsten ions have been studied theoretically. multiconfiguration Dirac-Hartree-Fock (MCDHF) method the large-scale relativistic configuration-interaction (CI) employed order to take into account electron correlation effects on wavelengths transition rates. It was found that rates obtained from MCDHF-CI depend strongly size type of active space used calculations. has extending orbitals without careful control...

The numerical simulations of Cu Kα and Kβ fluorescence lines induced by Rh X-ray tube monoenergetic radiation have been presented. copper Kβ/Kα intensity ratios for pure elements as well Ag-Cu alloys modeled. results obtained use the FLUKA code, based on Monte-Carlo approach, compared to available experimental theoretical values. A visible relationship was found between simulated content alloy: increases, coefficient decreases. can play role in elemental material analysis, especially archaeometry.

The ED-XRF (Energy-Dispersive X-ray Fluorescence) measurements and the FLUKA simulations have been made to discuss possibility of recognition coating layer as well its thickness measurement. In this work IKα(Cu)/IKα(Ag) intensity ratios IKβ(Ag)/IKα(Ag) IKβ(Cu)/IKα(Cu) for copper samples coated with various sputtered silver analyzed. results show strong dependence these factors thickness. performance method in archaeometry. Since use non-destructive methods during tests on ancient artifacts...

Studying $K$-shell hollow atom spectra broadens our knowledge on femtosecond phenomena in atomic physics, chemistry, and biology. Recent synchrotron measurements of the two-electron one-photon (TEOP) transitions low-$Z$ atoms have shown discrepancies between experiment theoretical predictions TEOP relative intensities their linewidths. The seem to be a result an incomplete description response strong perturbation due double photoionization (DPI). A attempt, based multiconfiguration...

The $K$-shell level radiative, nonradiative, and total widths, fluorescence yields, hole state lifetimes for atoms with $20\ensuremath{\le}Z\ensuremath{\le}30$ have been calculated in a fully relativistic way using the extensive multiconfiguration Dirac-Fock calculations inclusion of Breit interaction QED corrections also Dirac-Hartree-Slater calculations.

Extensive multiconfiguration Dirac-Fock calculations with the inclusion of transverse (Breit) interaction and QED corrections have been carried out on gold thorium to elucidate structure various satellite (additional vacancies in N and/or O shells) hypersatellite M or Mα1,2 (M5N6,7) Mβ1 (M4N6) lines its X-ray spectra. For every calculated type Mβ 1 theoretical stick spectra (line positions their relative intensities) presented. Moreover for each two predicted: one being a sum Lorentzian...

In the present work, an alternative approach for evaluation of equilibrium $K$-, $L$-, and $M$-shell ionizations mean charge state $\overline{q}$ projectiles passing through various targets has been proposed. The is based on measured $K$ x-ray energy shifts line intensity ratios utilizes theoretical analysis projectile spectra using multiconfiguration Dirac-Fock calculations. It was applied satellite hypersatellite lines in emitted by sulfur with energies 9.6--122 MeV carbon, aluminium,...

Results of relativistic calculations nuclear magnetic resonance shielding tensors ($\sigma$) for the thallium monocation (Tl$^+$), hydride (TlH) and halides (TlF, TlCl, TlBr, TlI, TlAt) are presented as obtained within a four-component polarization propagator formalism two-component linear response approach zeroth-order regular approximation. Additionally, some quantum electrodynamical (QED) effects on those NMR shieldings estimated. A strong dependence $\sigma$(Tl) bonding partner is found,...

Theoretical considerations are made for the nuclear excitation from ground state to 8 eV $^{229m}$Th isomer via near-resonant electron transitions in Sb-like ($q=39+$) thorium ions. The energy of first excited atomic ($J=7/2$) $^{229}$Th$^{39+}$ ion is estimated be 8.308$\pm$0.011 eV, which very close new reference value energy, 8.338$\pm$0.024 [Kraemer et al., Nature 617, 706 (2023)]. It was found that within uncertainty range both and energies, rate by transition can vary more than 20...