Statistical and quantum photoionization cross sections in plasmas: Analytical approaches for any configurations including inner shells
Statistical models combined with the local plasma frequency approach applied to the atomic electron density are employed to study the photoionization cross-section for complex atoms. It is demonstrated that the Thomas–Fermi atom provides surprisingly good overall agreement even for complex outer-she...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2020-11-01
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| Series: | Matter and Radiation at Extremes |
| Online Access: | http://dx.doi.org/10.1063/5.0022751 |
| _version_ | 1818445809070374912 |
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| author | F. B. Rosmej L. A. Vainshtein V. A. Astapenko V. S. Lisitsa |
| author_facet | F. B. Rosmej L. A. Vainshtein V. A. Astapenko V. S. Lisitsa |
| author_sort | F. B. Rosmej |
| collection | DOAJ |
| description | Statistical models combined with the local plasma frequency approach applied to the atomic electron density are employed to study the photoionization cross-section for complex atoms. It is demonstrated that the Thomas–Fermi atom provides surprisingly good overall agreement even for complex outer-shell configurations, where quantum mechanical approaches that include electron correlations are exceedingly difficult. Quantum mechanical photoionization calculations are studied with respect to energy and nl quantum number for hydrogen-like and non-hydrogen-like atoms and ions. A generalized scaled photoionization model (GSPM) based on the simultaneous introduction of effective charges for non-H-like energies and scaling charges for the reduced energy scale allows the development of analytical formulas for all states nl. Explicit expressions for nl = 1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f, and 5s are obtained. Application to H-like and non-H-like atoms and ions and to neutral atoms demonstrates the universality of the scaled analytical approach including inner-shell photoionization. Likewise, GSPM describes the near-threshold behavior and high-energy asymptotes well. Finally, we discuss the various models and the correspondence principle along with experimental data and with respect to a good compromise between generality and precision. The results are also relevant to large-scale integrated light–matter interaction simulations, e.g., X-ray free-electron laser interactions with matter or photoionization driven by a broadband radiation field such as Planckian radiation. |
| first_indexed | 2024-12-14T19:37:43Z |
| format | Article |
| id | doaj.art-f558256af34447dfaa46f3ae8d309f81 |
| institution | Directory Open Access Journal |
| issn | 2468-080X |
| language | English |
| last_indexed | 2024-12-14T19:37:43Z |
| publishDate | 2020-11-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | Matter and Radiation at Extremes |
| spelling | doaj.art-f558256af34447dfaa46f3ae8d309f812022-12-21T22:49:51ZengAIP Publishing LLCMatter and Radiation at Extremes2468-080X2020-11-0156064202064202-1510.1063/5.0022751Statistical and quantum photoionization cross sections in plasmas: Analytical approaches for any configurations including inner shellsF. B. Rosmej0L. A. Vainshtein1V. A. Astapenko2V. S. Lisitsa3Sorbonne University, Faculty of Science and Engineering, UMR 7605, case 128, 4 Place Jussieu, F-75252 Paris Cedex 05, FranceP. N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow 119991, RussiaMoscow Institute of Physics and Technology MIPT (National Research University), Dolgoprudnyi 141700, RussiaMoscow Institute of Physics and Technology MIPT (National Research University), Dolgoprudnyi 141700, RussiaStatistical models combined with the local plasma frequency approach applied to the atomic electron density are employed to study the photoionization cross-section for complex atoms. It is demonstrated that the Thomas–Fermi atom provides surprisingly good overall agreement even for complex outer-shell configurations, where quantum mechanical approaches that include electron correlations are exceedingly difficult. Quantum mechanical photoionization calculations are studied with respect to energy and nl quantum number for hydrogen-like and non-hydrogen-like atoms and ions. A generalized scaled photoionization model (GSPM) based on the simultaneous introduction of effective charges for non-H-like energies and scaling charges for the reduced energy scale allows the development of analytical formulas for all states nl. Explicit expressions for nl = 1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f, and 5s are obtained. Application to H-like and non-H-like atoms and ions and to neutral atoms demonstrates the universality of the scaled analytical approach including inner-shell photoionization. Likewise, GSPM describes the near-threshold behavior and high-energy asymptotes well. Finally, we discuss the various models and the correspondence principle along with experimental data and with respect to a good compromise between generality and precision. The results are also relevant to large-scale integrated light–matter interaction simulations, e.g., X-ray free-electron laser interactions with matter or photoionization driven by a broadband radiation field such as Planckian radiation.http://dx.doi.org/10.1063/5.0022751 |
| spellingShingle | F. B. Rosmej L. A. Vainshtein V. A. Astapenko V. S. Lisitsa Statistical and quantum photoionization cross sections in plasmas: Analytical approaches for any configurations including inner shells Matter and Radiation at Extremes |
| title | Statistical and quantum photoionization cross sections in plasmas: Analytical approaches for any configurations including inner shells |
| title_full | Statistical and quantum photoionization cross sections in plasmas: Analytical approaches for any configurations including inner shells |
| title_fullStr | Statistical and quantum photoionization cross sections in plasmas: Analytical approaches for any configurations including inner shells |
| title_full_unstemmed | Statistical and quantum photoionization cross sections in plasmas: Analytical approaches for any configurations including inner shells |
| title_short | Statistical and quantum photoionization cross sections in plasmas: Analytical approaches for any configurations including inner shells |
| title_sort | statistical and quantum photoionization cross sections in plasmas analytical approaches for any configurations including inner shells |
| url | http://dx.doi.org/10.1063/5.0022751 |
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