Measurements of extreme uv opacities in hot dense Al, Fe, and Ho

Winhart, G.; Eidmann, K.; Iglesias, Carlos A.; Bar‐Shalom, A.

doi:10.1103/physreve.53.r1332

Cited by 86 publications

(70 citation statements)

References 17 publications

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“…For this purpose, we have calculated the IPDs of the Al III and Al XI ions under the same experimental plasma conditions using both the Debye model and IS model at the intermediate plasma coupling. Under the experimental condition [44] with the ion density n i = 0.2 × 10 21 /cc and the temperature 20 eV (which correspond to D = 11.36 a.u. and R = 20 a.u.…”

Section: Debye Versus Is Model Resultsmentioning

confidence: 99%

Plasma screening effects on the electronic structure of multiply charged Al ions using Debye and ion-sphere models

2016

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We analyze atomic structures of plasma embedded aluminum (Al) atom and its ions in the weakly and strongly coupling regimes. The plasma screening effects in these atomic systems are accounted for using the Debye and ion sphere (IS) potentials for the weakly coupling and strongly coupling plasmas, respectively. Within the Debye model, special attention is given to investigate the spherical and non-spherical plasma-screening effects considering in the electron-electron interaction potential. The relativistic coupled-cluster (RCC) method has been employed to describe the relativistic and electronic correlation effects in the above atomic systems. The variation in the ionization potentials (IPs) and excitation energies (EEs) of the plasma embedded Al ions are presented. It is found that the atomic systems exhibit more stability when the exact screening effects are taken into account. It is also showed that in the presence of strongly coupled plasma environment, the highly ionized Al ions show blue and red shifts in the spectral lines of the transitions between the states with same and different principal quantum numbers, respectively. Comparison among the results obtained from the Debye and IS models are also carried out considering similar plasma conditions.

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Section: Debye Versus Is Model Resultsmentioning

confidence: 99%

Plasma screening effects on the electronic structure of multiply charged Al ions using Debye and ion-sphere models

2016

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“…Accurate radiative atomic data are also needed in opacity calculations (Winhart et al 1996). With the increased availability of high-resolution satellite observatories, emission lines from iron ions have been recorded in more detail.…”

Section: Introductionmentioning

confidence: 99%

EFFECTIVE COLLISION STRENGTHS FOR ELECTRON-IMPACT EXCITATION OF Fe VIII

Tayal

Zatsarinny

2011

ApJ

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New extensive calculations are reported for electron collision strengths, rate coefficients, and transition probabilities for the astrophysically important lines of Fe viii. The collision strengths have been calculated in the close-coupling approximation using the B-spline Breit-Pauli R-matrix method. The multiconfiguration Hartree-Fock method with term-dependent non-orthogonal orbitals is employed for an accurate representation of the target wave functions. The close-coupling expansion includes 102 fine-structure levels of Fe viii covering all possible terms of the ground 3p 6 3d and singly excited 3p 5 3d 2 , 3p 6 4l, 3p 5 3d4s, 3s3p 6 3d 2 , and 3p 6 5l configurations. The present calculations are more extensive than the previous ones, leading to a total 5151 transitions between fine-structure levels. The effective collision strengths are obtained by averaging the electron collision strengths over a Maxwellian distribution of velocities and these are tabulated for all fine-structure transitions at electron temperatures in the range from 5 × 10 3 to 5 × 10 6 K. There is an overall good agreement with the previous 77-state calculations by Griffin, Pindzola, & Badnell, but significant differences are also noted for some transitions.

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“…The authors would like to thank all the authors of References [27][28][29][30][31]33,34] for the experimental spectra as well as J. Colgan for providing the ATOMIC spectra.…”

Section: Acknowledgmentsmentioning

confidence: 99%

“…The areal mass is equal to 54 µg/cm 2 . Right: aluminum spectrum measured by Winhart et al [28,29] on ASTERIX IV laser facility in Germany and interpreted by SCO-RCG at ρ = 0.01 g/cm 3 and averaged over four temperatures (T = 18, 20, 22 and 24 eV) in order to simulate the gradients. The areal mass is equal to 30 µg/cm 2 .…”

Section: Interpretation Of Experimentsmentioning

confidence: 99%

“…Figure 1 (left) shows that the spectrum can be interpreted with a rather high accuracy (except maybe as concerns the main feature around 1530 eV) using SCO-RCG at a single temperature and a single density. The spectrally-resolved transmission of aluminum was measured in the range of 70-280 eV at ρ = 0.01 g/cm 3 and T = 22 eV [28,29]. For this purpose, the iodine laser ASTERIX IV (200 J energy with pulse duration 0.4 ns at 400 nm) was focused into a spherical gold cavity with a diameter of 3 mm.…”

Section: Interpretation Of Experimentsmentioning

confidence: 99%

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Detailed Opacity Calculations for Astrophysical Applications

Pain

Gilleron

Comet

2017

Atoms

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Nowadays, several opacity codes are able to provide data for stellar structure models, but the computed opacities may show significant differences. In this work, we present state-of-the-art precise spectral opacity calculations, illustrated by stellar applications. The essential role of laboratory experiments to check the quality of the computed data is underlined. We review some X-ray and XUV laser and Z-pinch photo-absorption measurements as well as X-ray emission spectroscopy experiments involving hot dense plasmas produced by ultra-high-intensity laser irradiation. The measured spectra are systematically compared with the fine-structure opacity code SCO-RCG. The focus is on iron, due to its crucial role in understanding asteroseismic observations of β Cephei-type and Slowly Pulsating B stars, as well as of the Sun. For instance, in β Cephei-type stars, the iron-group opacity peak excites acoustic modes through the "kappa-mechanism". Particular attention is paid to the higher-than-predicted iron opacity measured at the Sandia Z-machine at solar interior conditions. We discuss some theoretical aspects such as density effects, photo-ionization, autoionization or the "filling-the-gap" effect of highly excited states.

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Measurements of extreme uv opacities in hot dense Al, Fe, and Ho

Cited by 86 publications

References 17 publications

Plasma screening effects on the electronic structure of multiply charged Al ions using Debye and ion-sphere models

Plasma screening effects on the electronic structure of multiply charged Al ions using Debye and ion-sphere models

EFFECTIVE COLLISION STRENGTHS FOR ELECTRON-IMPACT EXCITATION OF Fe VIII

Detailed Opacity Calculations for Astrophysical Applications

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