Date of Award

Fall 12-15-2010

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physics and Astronomy

First Advisor

Steven T. Manson

Second Advisor

Daniel M. Crenshaw

Third Advisor

Xiaochun He

Fourth Advisor

Mark Stockman

Fifth Advisor

Brian Thoms

Abstract

Photoionization cross section calculations are performed for the ground ([Ne]3s23p63d 2D ) and the first two excited ([Ne]3s23p63d 2D and [Ne]3s23p64s 2S ) states of potassium-like transition metal ions (Sc+2, Ti+3, V+4, Cr+5, Mn+6, Fe+7), along with photoionization calculations for K-like Ca+ ions in the ground ([Ne]3s23p64s 2S ) state and the first two excited ([Ne]3s23p63d 2D and [Ne]3s23p63d 2D ) states. The discrete N-electron final state ion system orbitals are generated using the computer program AUTOSTRUCTURE; 24 configurations are included in the configuration-interaction (CI) calculation for transition metal ions, and 30 configurations for the case of Ca+ ions. The initial and final (N+1)-electron wavefunctions are generated using R-matrix along with photoionization cross sections. In addition to the non-relativistic (LS-coupling) R-matrix, we have used the relativistic (Breit-Pauli) R -matrix method to carry out these calculations to focus on relativistic effects. Relativistic and non-relativistic results are compared to demonstrate the influence of relativistic effects. The prominent 3p → 3d giant resonances are analyzed and identified, and our calculated positions and widths are compared with experimental results for K-like ions such as Ca+, Sc+2 and Ti+3. In the case of lower Z (22  Z  20) ions (Ca+, Sc+2 and Ti+3), the photoionization cross section spectra are dominated by the giant (3p  3d excitation) resonances, while in cases of higher Z (26  Z  23) ions (V+4, Cr+5, Mn+6 and Fe+7), the 3p  3d resonances lie below the ionization threshold, and the cross sections are dominated by 3p53d nd and 3p53d n’s Rydberg series of resonances. Comparison of the Ca+, Sc+2 and Ti3+ results with available theoretical and experimental data shows good agreement.

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