Two-electron one-photon transitions in atoms with 12 ⩽<i>Z</i>⩽ 80

Kadrekar, Riddhi; Natarajan, L.

doi:10.1088/0953-4075/43/15/155001

Cited by 13 publications

(13 citation statements)

References 34 publications

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“…The present K h to K h ratios compare best to the most recent relativistic configuration interaction calculations [21,29] and to the many-body perturbation theory predictions [12,14,15]. The branching ratios of Å berg, Jamison, and Richard [11] and Gavrila and Hansen [17] based on the relaxation of the initial and final states and the nonorthogonality of the Hartree-Fock orbitals are, however, underestimated.…”

Section: Fig 3 (Color Online)supporting

confidence: 75%

“…Thus data from HI collision experiments show a wide spread of values [6][7][8][9][10], making comparison with theory often inconclusive. On the theoretical side, significant differences in the predicted TEOP radiative decay rates have been reported [11][12][13][14][15][16][17][18][19][20][21]. In this respect, photon impact data provide a more stringent test for atomic structure calculations.…”

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confidence: 99%

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First Observation of Two-Electron One-Photon Transitions in Single-PhotonK-Shell Double Ionization

et al. 2011

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Experimental evidence for the correlated two-electron one-photon transitions (1s À2 ! 2s À1 2p À1 ) following single-photon K-shell double ionization is reported. The double K-shell vacancy states in solid Mg, Al, and Si were produced by means of monochromatized synchrotron radiation, and the two-electron one-photon radiative transitions were observed by using a wavelength dispersive spectrometer. The two-electron one-photon transition energies and the branching ratios of the radiative one-electron to twoelectron transitions were determined and compared to available perturbation theory predictions and configuration interaction calculations.Understanding electron-electron interactions in ionization, excitation, and relaxation of many-body systems is one of the key issues of atomic physics. In this context of special interest are hollow atoms, i.e., atoms with empty innermost shells and occupied outer shells, because singlephoton double K-shell ionization is driven by multielectron interactions (see [1,2], and references therein), and the decay of K-shell hollow atoms involves electron correlation effects. Furthermore, hollow atom formation in ultraintense hard x-ray free-electron laser beams reveals electron dynamics on the femtosecond time scale [3].In response to a K-shell doubly excited state, electron relaxation and rearrangement processes follow. The excited atom decays in a cascade of nonradiative Auger and radiative transitions. The radiative decay of double K-shell hole states proceeds mainly through the oneelectron one-photon (OEOP) process, which corresponds to the K h ð1s À2 ! 1s À1 2p À1 Þ hypersatellite transition. In the few orders of magnitude weaker competitive decay channel, the two-electron one-photon (TEOP) transition K h ð1s À2 ! 2s À1 2p À1 Þ, the two K-shell core holes are filled simultaneously via a correlated two-electron jump and one photon is emitted (see Fig. 1). TEOP transitions are thus correlated multielectron processes which can be described only by many-electron models.Interest in TEOP transitions dates back to 1925. Predicted by Heisenberg [4], it was only 50 years later that the first experimental evidence for TEOP transitions in heavy-ion (HI) collisions was reported by Wölfli et al. [5]. Although the K h to K h branching ratio should not depend on the excitation mode, multiple electron ionization in HI collisions changes the electronic configurations and affects the intensities and energies of the measured transitions. Thus data from HI collision experiments show a wide spread of values [6][7][8][9][10], making comparison with theory often inconclusive. On the theoretical side, significant differences in the predicted TEOP radiative decay rates have been reported [11][12][13][14][15][16][17][18][19][20][21]. In this respect, photon impact data provide a more stringent test for atomic structure calculations. However, the single-photon double K-shell ionization cross sections are $10 3 smaller than in HI collisions. Thus photoionization experiments are more challenging, and, to t...

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Section: Fig 3 (Color Online)supporting

confidence: 75%

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confidence: 99%

First Observation of Two-Electron One-Photon Transitions in Single-PhotonK-Shell Double Ionization

et al. 2011

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“…The predictions ofÅberg et al [65], Gavrila and Hansen [66], Baptista [67], Costa et al [68], and Saha et al [56] underestimate our experimental branching ratios. The BR values compare best to the most recent relativistic configuration interaction (RCI) calculations of Kadrekar and Natarajan [57,53] and to the many-body perturbation theory predictions [69][70][71]. Noteworthy is the good agreement of the RCI calculations [57,53] with the experimental branching ratio for Al when the coupling between the inner-shell vacancies and the outer incomplete subshells is included.…”

Section: One-electron One-photon To Two-electron One-photon Branchingsupporting

confidence: 62%

“…The BR values compare best to the most recent relativistic configuration interaction (RCI) calculations of Kadrekar and Natarajan [57,53] and to the many-body perturbation theory predictions [69][70][71]. Noteworthy is the good agreement of the RCI calculations [57,53] with the experimental branching ratio for Al when the coupling between the inner-shell vacancies and the outer incomplete subshells is included. The reported results give an important point of comparison for different theoretical models that address the many-body problem and demonstrate the potential of the TEOP radiative decay of K-shell hollow atoms to unravel electron correlations.…”

Section: One-electron One-photon To Two-electron One-photon Branchingsupporting

confidence: 62%

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Photoinduced K-shell hollow atoms

Hoszowska

Dousse

2013

Journal of Electron Spectroscopy and Related Phenomena

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The mechanisms leading to the production of hollow K shell atoms via single photon impact were investigated for a variety of light elements with 12 ≤ Z ≤ 23. The double 1s vacancy states were produced by irradiating the samples with intense monoenergetic synchrotron radiation beams. The double-to-single K-shell photoionization probabilities P KK and the absolute double K-shell photoionization cross sections 2+ were determined by measuring with a high-resolution bent von Hamos crystal spectrometer the K˛h hypersatellite X-ray emission of the samples. The measurements were performed over a wide range of incoming photon energies from threshold up to energies beyond the broad maximum of the double-tosingle photoionization cross section ratios. The P KK and 2+ were determined from the relative yields of the resolved K˛h hypersatellite lines. For Mg, Al and Si, the two-electron one-photon (TEOP) K˛˛h transitions which represent an alternative but much weaker decay channel for double 1s vacancy states could be also observed, using a highly efficient flat crystal wavelength dispersive spectrometer. This observation of single photon-induced TEOP transitions has shown that the I(K˛h)/I(K˛˛h) branching ratios are very poorly reproduced by most of existing theoretical models. Besides the relative yields of the hypersatellite and TEOP transitions, the energies and natural linewidths of the K˛h and K˛˛h X-ray lines were also determined. The energies are found to be in good agreement with different theoretical predictions, whereas the linewidths are significantly underestimated by the calculations, except if non-lifetime broadening effects such as the outer-shell ionization and the open valence configuration are taken into consideration.

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Energy levels and radiative transition properties of the 2s2p double K-shell vacancy state in He-like ions (4≤Z≤54)

Ding

Cao

et al. 2023

Atomic Data and Nuclear Data Tables

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Two-electron one-photon transitions in atoms with 12 ⩽Z⩽ 80

Cited by 13 publications

References 34 publications

First Observation of Two-Electron One-Photon Transitions in Single-PhotonK-Shell Double Ionization

First Observation of Two-Electron One-Photon Transitions in Single-PhotonK-Shell Double Ionization

Photoinduced K-shell hollow atoms

Energy levels and radiative transition properties of the 2s2p double K-shell vacancy state in He-like ions (4≤Z≤54)

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