Effect of distortion in electron impact excitation in Coulomb-projected Born approximation

Pramana ◽  
1992 ◽  
Vol 38 (1) ◽  
pp. 77-90
Author(s):  
V Kumar ◽  
B N Roy ◽  
D K Rai
Keyword(s):  
Electron Impact ◽  
Born Approximation ◽  
Impact Excitation ◽  
Electron Impact Excitation

scholarly journals Electron Impact Excitation Cross Sections for B III

1983 ◽  
Vol 36 (5) ◽  
pp. 659
Author(s):  
PS Ganas ◽  
M Aryafar ◽  
LP Gately
Keyword(s):  
Electron Impact ◽  
Excited States ◽  
Cross Sections ◽  
Born Approximation ◽  
Oscillator Strengths ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Central Potential ◽  
Excitation Cross Sections ◽  
Generalized Oscillator

A realistic analytical central potential with two adjustable parameters is used to generate wavefunctions for the ground and excited states of doubly ionized boron. Generalized oscillator strengths and integrated cross sections from threshold up to 5 keY are calculated in the Born approximation for 2s-ns, 2s-np and 2s-nd excitations. Convenient analytic formulae for the cross sections are presented.

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.

The 1 s -2 s excitation of hydrogen atoms by electron impact

1960 ◽  
Vol 258 (1293) ◽  
pp. 245-250 ◽  
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Cross Sections ◽  
Born Approximation ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Hydrogen Atoms ◽  
Third Order ◽  
The Third ◽  
Intermediate States

The expression for the cross-section obtained from the second Born approximation by including only terms to the third order in the interaction energy is employed to calculate cross-sections for the electron impact excitation of the 2 s level of atomic hydrogen, allow­ance being made for distortion and polarization due to the 1 s , 2 s and 2 p 0.± 1 intermediate states. These cross-sections are compared with the available experimental data.

Collisional Excitation of Ground State Hydrogenic Ions

1973 ◽  
Vol 51 (19) ◽  
pp. 2047-2053 ◽  
Author(s):  
John A. Tully
Keyword(s):  
Electron Impact ◽  
Electron Energy ◽  
Ground State ◽  
Born Approximation ◽  
Incident Electron ◽  
Impact Excitation ◽  
Incident Electron Energy ◽  
Electron Impact Excitation ◽  
Collisional Excitation ◽  
Hydrogenic Ions

The nonrelativistic Coulomb–Born approximation has been used to compute scaled collision strengths for electron impact excitation of the 1s → ns, np, nd transitions in hydrogenic ions. Results are given for n = 2, 3, 4, 5, 6, [Formula: see text] as a function of the incident electron energy in threshold units. Simple formulae for interpolating the tabulated results are also given.

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

2001 ◽  
Vol 11 (PR2) ◽  
pp. Pr2-309-Pr2-312
Author(s):  
K. M. Aggarwal ◽  
F. P. Keenan ◽  
S. J. Rose
Keyword(s):  
Electron Impact ◽  
Impact Excitation ◽  
Rate Coefficients ◽  
Electron Impact Excitation

EXPERIMENTS ON ELECTRON IMPACT EXCITATION AND DIELECTRONIC RECOMBINATION AT HARVARD-SMITHSONIAN

1989 ◽  
Vol 50 (C1) ◽  
pp. C1-405-C1-409
Author(s):  
L. D. GARDNER ◽  
J. L. KOHL ◽  
D. W. SAVIN ◽  
A. R. YOUNG
Keyword(s):  
Electron Impact ◽  
Dielectronic Recombination ◽  
Impact Excitation ◽  
Electron Impact Excitation
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