Atomic and optical properties of warm dense copper

Miloshevsky, G.; Hassanein, A.

doi:10.1103/physreve.92.033109

Cited by 13 publications

(8 citation statements)

References 43 publications

(61 reference statements)

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“…The fact that the band gap does not go to zero over the examined compression range means that DFT-MD does not predict any pressure ionization of the L shell for 12fold compression or lower. We juxtapose our DFT-MD curve with atomic ionization energy calculations from a recent atomic-kinetics model (REODP) [126] that incorporates continuum lowering based on the ion-sphere model known as Stewart-Pyatt [127]. The results differ in that the atomic models predict that the ionization energy goes to zero before 12-fold compression, indicating L-shell pressure ionization.…”

Section: Electronic Density Of States and Ionization Behaviormentioning

confidence: 99%

Path integral Monte Carlo simulations of warm dense aluminum

2018

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We perform first-principles path integral Monte Carlo (PIMC) and density functional theory molecular dynamics (DFT-MD) calculations to explore warm dense matter states of aluminum. Our equation of state (EOS) simulations cover a wide density-temperature range of 0.1-32.4gcm^{-3} and 10^{4}-10^{8} K. Since PIMC and DFT-MD accurately treat effects of the atomic shell structure, we find two compression maxima along the principal Hugoniot curve attributed to K-shell and L-shell ionization. The results provide a benchmark for widely used EOS tables, such as SESAME, QEOS, and models based on Thomas-Fermi and average-atom techniques. A subsequent multishock analysis provides a quantitative assessment for how much heating occurs relative to an isentrope in multishock experiments. Finally, we compute heat capacity, pair-correlation functions, the electronic density of states, and 〈Z〉 to reveal the evolution of the plasma structure and ionization behavior.

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Section: Electronic Density Of States and Ionization Behaviormentioning

confidence: 99%

Path integral Monte Carlo simulations of warm dense aluminum

2018

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“…Next, we examine the emission spectrum of carbon plasma at a temperature of 50 eV and the plasma density of 4.3 × 10 −3 g/cm 3 . A comparison of STA emission spectrum with those obtained using the non-LTE DLAYZ code [53] and REODP code [54] is displayed in Fig. 4.…”

Section: A Comparison Of Theories and Experiments For Carbon Plasmamentioning

confidence: 99%

“…Following [53,54], we also have the locations of the 1s ionization thresholds of C III, C IV, and C V ions, and the He-α, He-β, Lyman-α, and Lyman-β emission lines marked in the figure. And from these markers, we notice that the STA calculated somewhat lower ionization edges for C IV and C V ions.…”

Section: A Comparison Of Theories and Experiments For Carbon Plasmamentioning

confidence: 99%

“…Figure5(a) shows the opacity of carbon plasmas at the density of 2.24 g/cm3 and a temperature of 100 eV. The STA result is compared with the spectra calculated using another variant of Dirac-Fock-Slater DLA model (DF-DLA) by Gao et al[55] and the REODP code[54]. The STA-computed absorption spectra and line positions are reasonably consistent with respect to the results of the other two calculations, except below the photon energy of 280 eV where the STA-obtained opacities are much lower.…”

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confidence: 99%

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Radiative and atomic properties of C and CH plasmas in the warm-dense-matter regime

et al. 2018

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A theoretical model based on the method of super transition arrays (STA) is used to compute the emissivities, opacities and average ionization states of carbon (C) and polystyrene (CH) plasmas in the warm-dense matter regime in which the coupling constant varies between 0.02 to 2.0. The accuracy of results of STA calculations is assessed by benchmarking against the available experimental data and results obtained using other theoretical methods, assuming that a state of local thermodynamic equilibrium exists in the plasma. In the case of a carbon plasma, the STA method yields spectral features that are in reasonably-good agreement with Dirac-Fock and Hartree-Fock-Slater theories; in the case of CH, we find that STA-derived opacities are very similar to those derived using quantum-molecular-dynamics density-functional theory and Hartree-Fock method down to plasma temperature of about 20 eV. Our calculations also compare favorably with available experimental measurements of Gamboa et al [High Energy Density Phys. 11, 75 (2014)] of the plasma temperature and average ionization state behind a blast wave in a pure carbon foam. Although the STA-computed average-ionization charge state in the rarefaction region appears to be lower than the experimental data, it is within the experimental uncertainty and the discrepancy is nevertheless consistent with results reported using an atomic kinetic model. In addition, we further predict the temperature dependence of average ionization states of CH plasma in the same temperature range as for the carbon plasma.

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“…Collisional interactions between electrons and ions play a fundamental role in describing the non-equilibrium behaviour of plasmas in the warm-and hot-dense matter regimes. They directly influence the charge state distribution [1], and hence indirectly plasma transport properties [2][3][4], optical properties [5,6] and equilibration timescales [7]. A detailed understanding of collisional mechanisms is of great practical importance for research in inertial confinement fusion [8] and in astrophysical plasmas [9].…”

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confidence: 99%

Clocking Femtosecond Collisional Dynamics via Resonant X-Ray Spectroscopy

et al. 2018

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Electron-ion collisional dynamics is of fundamental importance in determining plasma transport properties, nonequilibrium plasma evolution, and electron damage in diffraction imaging applications using bright x-ray free-electron lasers (FELs). Here we describe the first experimental measurements of ultrafast electron impact collisional ionization dynamics using resonant core-hole spectroscopy in a solid-density magnesium plasma, created and diagnosed with the Linac Coherent Light Source x-ray FEL. By resonantly pumping the 1s→2p transition in highly charged ions within an optically thin plasma, we have measured how off-resonance charge states are populated via collisional processes on femtosecond time scales. We present a collisional cross section model that matches our results and demonstrates how the cross sections are enhanced by dense-plasma effects including continuum lowering. Nonlocal thermodynamic equilibrium collisional radiative simulations show excellent agreement with the experimental results and provide new insight on collisional ionization and three-body-recombination processes in the dense-plasma regime.

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Atomic and optical properties of warm dense copper

Cited by 13 publications

References 43 publications

Path integral Monte Carlo simulations of warm dense aluminum

Path integral Monte Carlo simulations of warm dense aluminum

Radiative and atomic properties of C and CH plasmas in the warm-dense-matter regime

Clocking Femtosecond Collisional Dynamics via Resonant X-Ray Spectroscopy

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