RelativisticR-matrix close-coupling method based on the effective many-body Hamiltonian: electron-impact excitation of electric dipole-allowed and spin-forbidden transitions of the S4 +ion

2010 ◽  
Vol 43 (7) ◽  
pp. 074030 ◽  
Author(s):  
Juan A Santana ◽  
Yasuyuki Ishikawa
Keyword(s):  
Electron Impact ◽  
Electric Dipole ◽  
Coupling Method ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Many Body ◽  
Close Coupling ◽  
Forbidden Transitions

Relativistic R-matrix close-coupling method based on the effective many-body Hamiltonian: electron-impact excitation of the 3s2 1S0–3s3p1P1o electric dipole-allowed transition of the Ar6+ ion1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (4) ◽  
pp. 457-463
Author(s):  
Juan A. Santana ◽  
Yasuyuki Ishikawa
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Electric Dipole ◽  
Coupling Method ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Many Body ◽  
Close Coupling ◽  
R Matrix ◽  
Excitation Cross Sections

Electron-impact excitation cross sections of the electric dipole-allowed 3s2 1S0–3s3p [Formula: see text] transition in Mg-like argon (Ar6+) are calculated using the configuration-interaction and effective many-body Hamiltonian R-matrix close-coupling methods. The near-threshold electron-impact excitation cross sections computed with the effective many-body Hamiltonian R-matrix close-coupling method are in good agreement with the benchmark experimental results.

Calculation of electron-impact excitation and ionization of atoms and ions

1996 ◽  
Vol 74 (11-12) ◽  
pp. 875-882 ◽  
Author(s):  
Igor Bray
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Coupling Method ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Ionization Cross ◽  
Close Coupling ◽  
Spin Asymmetries ◽  
Total Ionization ◽  
Ionization Cross Sections

We present a review of applications of the convergent close-coupling method concentrating on spin-dependent electron-impact total ionization cross sections. The results for the electron-impact total ionization cross sections and the associated spin asymmetries of H, Li, O5+, Na, and He(23S) are reviewed, with new calculations being presented for the potassium target.

Excitation of Ne VIII by electron impact

1976 ◽  
Vol 54 (20) ◽  
pp. 2019-2023 ◽  
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.

scholarly journals Effective collision strengths for electron-impact excitation of Al10+

2006 ◽  
Vol 24 (2) ◽  
pp. 235-240 ◽  
Author(s):  
V. STANCALIE ◽  
V. PAIS
Keyword(s):  
Electron Impact ◽  
Maximum Energy ◽  
Impact Excitation ◽  
Electron Collision ◽  
Electron Impact Excitation ◽  
Coupling Scheme ◽  
Close Coupling ◽  
R Matrix ◽  
Intermediate Coupling Scheme ◽  
Effective Collision

Electron collision strengths for electron-impact excitation of Li-like and Al ion are evaluated in close-coupling approximation using the multi-channel R-matrix method. Five LS target eigenstates are included in the expansion of the total wave function, consisting of the twon= 2 states withconfigurationsof 1s22s, 1s22p, and threen= 3 states withconfigurations1s23s, 1s23p, and 1s23d. Collision strengths are obtained in LS coupling using FARM code and in intermediate coupling scheme using the SUPERSTRUCTURE program. The effective collision strengths are calculated as function of temperature, up to a temperature that does not exceed half of the maximum energy in the R-matrix run.

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