Energies and the radiative and Auger transition rates of1s2p4resonances of B-like ions

Abstract

Energy levels and the radiative and Auger transition rates of the 1s2p 4 2,4 L (L = S, P , D) resonances in the boron isoelectronic sequence are calculated using the saddle-point variation and saddle-point complex-rotation methods. Large-scale wave functions are used to saturate the functional space. Relativistic and mass polarization corrections are included by the first-order perturbation theory. The Auger branching ratios of the important decay channels for these core-excited states are calculated. The reliable transition wavelengths and Auger electron energies are used to identify available x-ray spectra and Auger electron spectra. Identifications of several unknown experimental lines from 1s2p 4 resonances are reported. The total radiative rates and total Auger rates of these 1s2p 4 resonances are also reported and discussed along with the increase of atomic number Z. It is found that the total Auger rates are several orders of magnitude greater than the total radiative rates in these low-Z ions.

K-shell photoionization of B-like oxygen (O3 +) ions: experiment and theory

“…Sun and co-workers [30] used the SPM with rotation to calculate energy levels and Auger decay widths for the 1s2s 2 2p 2 and 1s2s2p 3 2,4 L levels in B-like carbon and found suitable agreement with the re-calibrated spectrum of Bruch and co-workers [31] and the combined theoretical work and high resolution synchrotron measurements performed at the ALS [32]. In the case of O 3+ ions, recent saddle-point with rotation calculations by Sun and co-workers [33] for the energy levels and Auger and radiative decay rates for the 1s2s 2 2p 2 and 1s2s2p 3 2,4 L levels were compared to the earlier beam-foil experimental measurements of Bruch and co-workers [11], the MCDF work of Chen and Craseman [23,24] and further extended to the higher lying 1s2p 4 levels of other B-like ions [34].…”

Single and double K-shell resonant photoionization and Auger decay of 1s → 2p excited states of O+–O4+

“…Theoretically, earlier work by Chen et al (1997Chen et al ( , 1988Chen et al ( , 1987 investigated the K-shell Auger decay and radiative transitions for the carbon-like and boron-like ions including O 2+ and O 3+ using the multi-configuration DiracFock (MCDF) approach. For O 3+ , additional variety of methods such as 1/Z perturbation theory (Safronova & Shlyaptseva 1999) and the saddle-point-method with R-matrix, complex coordinate rotation methods (Chung 1990;Lin et al 2001Lin et al , 2002Sun et al 2011Sun et al , 2013 were used to calculate the Auger resonance energies and widths of K-shell excited states. Later, the K-shell Auger processes of O + -O 4+ were investigated by using the R-matrix method (Petrini 1981;Petrini & Da Silva 1996;Zeng et al 2001Zeng et al , 2004Zeng & Yuan 2002;Olalla et al 2002;Pradhan et al 2003;Garcia et al 2005), which represent the state-of-the-art ab initio calculations.…”

“…( f ) Saddle-point complex-rotation method computation from Sun et al (2013). (g) R-matrix computation from Garcia et al (2005).…”

X-ray wavelengths and Auger transition energies of 1s 2p4(2S,2,4P,2D) resonances in B-like (Z = 6–18) ions

“…In addition, some experimental lines of 1s2p 4 resonances in B-like ions from high-resolution Auger spectrum were observed by Bruch et al [3] and by Kádár et al [4]. On the theoretical side, calculations of Auger energies of the 1s 2p 4 ( 2 S, 2,4 P, 2 D) resonances in B-like ions have been performed using various ab initio methods such as the perturbation with super structure code (PSC) used by Safronova et al [5,6], the multiconfiguration Dirac-Fock (MCDF) approach employed by Chen and Crasemann [7], the unrestricted Hartree-Fock (UHF) self-consistent-field (SCF) method used by Bruch et al [3] and the saddle-point variation and SPCR technique utilized by Sun et al [8]. In the preceding experimental studies [1][2][3][4], various lines were not identified such as the not-identified O-like lines reported by Kádár et al [4].…”

“…In addition, some discrepancies in the above calculations [3,[5][6][7] are observed due mainly to strong electron correlation effects in B-like ions. The goal in the works of Sun et al [8] was to solve the preceding theoretical discrepancies and to identify some unknown experimental lines from 1s2p 4 resonances in B-Like C + , O 3+ and Ne 5+ ions. However, the high-relativistic calculations reported by Sun et al [8] have been limited to the 1s 2p 4 ( 2 S, 2,4 P, 2 D) resonances in B-like C + , O 3+ , Ne 5+ , Mg 7+ and Si 9+ ions.…”