Electron impact excitation of Al XIII : Collision strengths and rate coefficients

Electron-impact single- and double-ionization cross sections and Maxwellian rate coefficients are presented for the carbon atom. Scaling factors are introduced for the electron-impact excitation and ionization cross sections obtained in the distorted wave (DW) approximation. It is shown that the scaled DW cross sections provide good agreement with measurements for the single ionization of the C atom and C1+ ion. The direct double-ionization (DDI) process is studied using a multi-step approach. Ionization–ionization, excitation–ionization–ionization, and ionization–excitation–ionization branches are analyzed. It is demonstrated that the three-step processes contribute ≼40% of the total DDI cross sections for the case where one of the electrons takes all of the excess energy after the first ionization process.

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Calculations of Dielectronic Recombination and Electron-impact Excitation Rate Coefficients of Highly Charged Sulfur Ions

The Astrophysical Journal Supplement Series ◽

10.3847/1538-4365/ab6b2c ◽

2020 ◽

Vol 247 (1) ◽

pp. 22

Author(s):

D. H. Zhang ◽

Z. W. Wu ◽

C. Ren ◽

J. Jiang ◽

L. Y. Xie ◽

...

Keyword(s):

Electron Impact ◽

Dielectronic Recombination ◽

Impact Excitation ◽

Rate Coefficients ◽

Electron Impact Excitation ◽

Excitation Rate

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Calculation of electron-impact excitation and ionisation cross sections and reaction rate coefficients for C, N and O atoms

Journal of Physics Conference Series ◽

10.1088/1742-6596/1243/1/012014 ◽

2019 ◽

Vol 1243 ◽

pp. 012014

Author(s):

Ali Hleli ◽

Riadh Riahi ◽

Philippe Teulet ◽

Yann Cressault ◽

Hassen Ghalila

Keyword(s):

Electron Impact ◽

Cross Sections ◽

Reaction Rate ◽

Impact Excitation ◽

Rate Coefficients ◽

Electron Impact Excitation

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Excitation of Ne VIII by electron impact

Canadian Journal of Physics ◽

10.1139/p76-239 ◽

1976 ◽

Vol 54 (20) ◽

pp. 2019-2023 ◽

Cited By ~ 14

Author(s):

W. L. van Wyngaarden ◽

Ronald J. W. Henry

Keyword(s):

Electron Impact ◽

Born Approximation ◽

Experimental Error ◽

Rate Coefficient ◽

Impact Excitation ◽

Rate Coefficients ◽

Electron Impact Excitation ◽

Close Coupling ◽

Coupling Approximation ◽

Made In

Collision strengths for electron impact excitation of Ne VIII are calculated at 14, 18, and 30 Ry in a 5-state close coupling expansion and the unitarized Coulomb–Born approximation. To assess the importance of exchange and coupling beyond the 5 states, additional calculations are made at 18 Ry in 5-state and 8-state close coupling expansions without exchange. For the 2s–2p excitation, calculations below the 3s threshold at 10.0 Ry are made in a 2-state close coupling expansion at 1.6, 3.2, and 8.0 Ry. In most instances the close coupling method gives results which differ by 15% or less from those of the unitarized Coulomb–Born approximation and by 20–70% from the CBI (Coulomb–Born) results of Bely. Rate coefficients which are calculated from the results obtained in the close coupling approximation agree within experimental error with the experimental results of Kunze and Johnston and Haddad and McWhirter with the exception of the rate coefficient for the 2p → 3d excitation.

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