Relativistic Calculations of Excitation and Ionization of Highly Charged Ions by Electron Impact. Final Technical Report

Relativistic Calculations of Excitation and Ionization of Highly Charged Ions by Electron Impact. Final Technical Report

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Published: 1992

Total Pages: 13

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Our rapid relativistic atomic structure program and relativistic distorted-wave programs for excitation and ionization of highly charged ions were further improved. The generalized Briet interaction and other QED corrections were added to the atomic structure program, and the speed of the distorted-wave excitation program was increased by over an order of magnitude over what it was when our initial large-scale relativistic calculations of excitation of Ne-like ions were made. The improved programs were then used to calculate collision strengths for 330 transitions in F-like ions with 22 ≤ Z ≤ 92 and 248 transitions in Ni-like ions with 60 ≤ Z ≤ 92. We expanded the relativistic collision program to include an option to use atomic structure data by the well-known multi-configuration Dirac-Fock (MCDF) program of Grant and A coworkers. This was used in calculating collision strengths for the 45 [Delta]n = 0 transitions with n=2 in Be-like ions with 8 ≤ Z ≤ 92. This relativistic collision strength program was also extended to include an option to include the generalized Breis interaction in the scattering matrix elements and the importance of this for He-like, He-like and Li-like ions with Z = 26, 54 and 92 was studied. The factorization method was applied to ionization. Regardless of the complexity of the ion the ionization cross sections could be written as a sum of the products of a readily calculated coefficient that depends only on ion properties and a hydrogen-like cross section. Work was also done on excitation and ionization by directive and, in some cases spin-polarized electrons, which is of interest for some EBIT experiments and the study of solar flares. We also used our extensive collision strength results to test the.


Excitation and Ionization of Highly Charged Ions by Electron Impact

Excitation and Ionization of Highly Charged Ions by Electron Impact

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Published: 1989

Total Pages: 15

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Two approaches for very rapid calculation of atomic data for high temperature plasma modeling have been developed. The first uses hydrogenic basis states and has been developed and applied in many papers discussed in previous progress reports. Hence, it is only briefly discussed here. The second is a very rapid, yet accurate, fully relativistic approach that has been developed over the past two or three years. It is described in more detail. Recently it has been applied to large scale production of atomic data. Specifically, it has been used to calculate relativistic distorted wave collision strengths and oscillator strengths for the following: all transitions from the ground level to the n=3 and 4 excited levels in the 71 Neon-like ions with nuclear charge number Z in the range 22 (less-than or equal to) Z (less-than or equal to) 92; all transitions among the 2s{sub {1/2}}, 2p{sub {1/2}} and 2p32 levels and from them to all nlj levels with n=3,4 and 5 in the 85 Li-like ions with 8 (less-than or equal to) Z (less-than or equal to) 92; all transitions among the 3s{sub {1/2}}, 3p32, 3d32 and 3d52 levels and from them to all nlj levels with n=4 and 5 in the 71 Na-like ions with 22 (less-than or equal to) Z (less-than or equal to) 92; and all transitions among 4s{sub {1/2}}, 4p{sub {1/2}}, 4p32, 4d32, 4d52, 4f52 and 4f--2 levels and from them to all nlj levels with n=5 in the 33 Cu-like ions with 60 (less-than or equal to) Z (less-than or equal to) 92. Also the program has been extended to give cross-sections for excitation to specific magnetic sublevels of the target ion by an electron beam and very recently it has been extended to give relativistic distorted wave cross sections for ionization of highly charged ions by electron impact.


Excitation and Ionization of Highly Charged Ions by Electron Impact. Progress Report, April 1, 1976--December 15, 1976

Excitation and Ionization of Highly Charged Ions by Electron Impact. Progress Report, April 1, 1976--December 15, 1976

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Published: 1976

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Results have been obtained for the scaled cross sections for ionization from the 1s, 2s and 2p sublevels of hydrogenic ions with Z = infinity. A procedure has been given for obtaining approximate results for ionization of highly charged ions up through neon-like ions from these results. Additional results for excitation of hydrogenic ions with Z = infinity are being obtained. These can be used to obtain additional approximate results for complex ions. Criteria have been obtained for the validity of the assumption that the sublevels of hydrogenic ions are populated in proportion to their statistical weights. The results for many transitions in ions with three valence electrons have been expressed in a simple way in terms of the scaled hydrogenic ion collision strengths Z/sup 2/.cap omega./sub H/ and Z/sup 2/.cap omega./sup e//sub H/. Configuration mixed results for excitation of highly charged Be-like ions have been calculated for 66 transitions. Configuration mixed and parentage mixed results for inner-shell excitation of highly charged Li-like ions have been calculated for 96 transitions. The procedures and programs for calculating excitation cross sections for He-like ions with relativistic corrections are mostly completed and results for a large number of transitions are expected by the end of the contract year.