Atomic magnesium: II. One-photon transition probabilities and ionisation cross sections. A valence-shell L2CI calculation

K, L and M shell x-ray fluorescence cross sections have been measured for elements 11 ≤, Z ≤, 92 at excitation energies corresponding to weighted average energies of K-lines of Ti-K (4.558 keV), Fe-K (6,480 keV), Ge-K (10.024 keV), Se-K (11.391 keV) and Mo-K (17.805 keV) . The measurements were performed with an energy-dispersive x-ray spectrometer in a vacuum chamber using thin ultra-pure targets. Rh x-ray tube and secondary targets were used for excitation of x-ray radiation. The measured x-ray fluorescence cross-sections have been compared to previously published experimental and theoretical results. Presented data can be used for determination of physical parameters such as photoionization cross-sections, fluorescence yields, x-ray emission rates, Coster-Kronig transition probabilities and jump ratios.

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Oscillator strengths and integral cross sections of the valence-shell excitations of sulfur dioxide studied by fast electron impact

Journal of Physics B Atomic Molecular and Optical Physics ◽

10.1088/1361-6455/ab9dbe ◽

2020 ◽

Vol 53 (17) ◽

pp. 175103

Author(s):

Xiao-Jiao Du ◽

Yuan-Chen Xu ◽

Li-Han Wang ◽

Tian-Jun Li ◽

Zi-Ru Ma ◽

...

Keyword(s):

Sulfur Dioxide ◽

Electron Impact ◽

Cross Sections ◽

Fast Electron ◽

Oscillator Strengths ◽

Valence Shell

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Atomic Processes in Planetary Nebulae

Symposium - International Astronomical Union ◽

10.1017/s0074180900208942 ◽

2003 ◽

Vol 209 ◽

pp. 325-334

Author(s):

Sultana N. Nahar

Keyword(s):

Cross Sections ◽

Large Scale ◽

Transition Probabilities ◽

Central Star ◽

Dielectronic Recombination ◽

Impact Excitation ◽

Electron Impact Excitation ◽

Theoretical Treatment ◽

Atomic Processes ◽

Ion Recombination

A hot central star illuminating the surrounding ionized H II region usually produces very rich atomic spectra resulting from basic atomic processes: photoionization, electron-ion recombination, bound-bound radiative transitions, and collisional excitation of ions. Precise diagnostics of nebular spectra depend on accurate atomic parameters for these processes. Latest developments in theoretical computations are described, especially under two international collaborations known as the Opacity Project (OP) and the Iron Project (IP), that have yielded accurate and large-scale data for photoionization cross sections, transition probabilities, and collision strengths for electron impact excitation of most astrophysically abundant ions. As an extension of the two projects, a self-consistent and unified theoretical treatment of photoionization and electron-ion recombination has been developed where both the radiative and the dielectronic recombination processes are considered in an unified manner. Results from the Ohio State atomic-astrophysics group, and from the OP and IP collaborations, are presented. A description of the electronic web-interactive database, TIPTOPBASE, with the OP and the IP data, and a compilation of recommended data for effective collision strengths, is given.

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Atomic Physics Data for Stellar Atmospheres Research

Symposium - International Astronomical Union ◽

10.1017/s0074180900133418 ◽

2003 ◽

Vol 210 ◽

pp. 261-272

Author(s):

Charles R. Cowley ◽

Saul J. Adelman ◽

Donald J. Bord

Keyword(s):

Cross Sections ◽

Transition Probabilities ◽

Stellar Atmospheres ◽

Partition Functions ◽

Line Broadening ◽

Data Bases ◽

Stellar Spectra ◽

Atomic Ions ◽

Excitation Cross Sections ◽

Nuclear Effects

The review will cover the following topics: (1) Ionization energies; (2) Partition functions; (3) Sources of data for atomic and ionic wavelengths, transition probabilities, and broadening parameters, including nuclear effects (hfs and isotope shifts); (4) Opacities from photoionization of abundant elements (atoms and atomic ions) with emphasis on integration of TOPBASE material; and (5) Data bases for diatomic molecules. We emphasize topics of direct relevance to the synthesis of stellar spectra, primarily within the domain where LTE is useful. Additional parameters, such as line-broadening parameters, or excitation cross sections are not reviewed.

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