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Full-Text Articles in Physics
Trends In The Theory Of Atomic Photoionization, Anthony F. Starace
Trends In The Theory Of Atomic Photoionization, Anthony F. Starace
Anthony F. Starace Publications
For VUV photon energies, detailed theoretical understanding of the photoionization process has been achieved for the case of a single electron ionized from one of the outer subshells of a closed-shell atom. This understanding is based qualitatively upon a few properties of realistic atomic central potentials and quantitatively upon a few distinct types of electronic interactions known generically as particle-hole interactions. Current theoretical research is mainly directed at understanding a broader class of atomic photoionization phenomena involving, e.g., open-shell atoms, electronic interactions not of the particle-hole class, real two-electron processes, and external electric and magnetic fields.
Photoionization Cross Section For He In The Hyperspherical Coordinate Method, Donald L. Miller, Anthony F. Starace
Photoionization Cross Section For He In The Hyperspherical Coordinate Method, Donald L. Miller, Anthony F. Starace
Anthony F. Starace Publications
The hyperspherical coordinate method developed by Macek, Fano, Lin, and Klar to describe two-electron correlations is used for the first time to treat an atomic photoionization process. Using adiabatic approximations for both the initial and the final state, the cross section for the process He +γ +He+1s +e– is calculated and is found to lie 1% higher than the revised experimental data of Samson at threshold, 4% lower at 1 Ryd above threshold, and 12% lower at 1.9 Ryd above threshold.
Addendum To "Ab Initio Treatment Of Final-State Spin-Orbit Interactions: Photoionization Of The 6s Electron In Cesium", Keh-Ning Huang, Anthony F. Starace
Addendum To "Ab Initio Treatment Of Final-State Spin-Orbit Interactions: Photoionization Of The 6s Electron In Cesium", Keh-Ning Huang, Anthony F. Starace
Anthony F. Starace Publications
A previous calculation of the cesium 6s→εp photoionization cross section is extended to include interchannel coupling to the 5p→εd photoionization channels. For photon energies in the range 0.35 a.u.≲ℏω≲1.12 a.u., i.e., just above the near-threshold cross-section minimum, the 6s photoionization cross section is found to be dominated by 5p→5d resonance transitions. No experimental data exist for this energy region.
Photoionization Of The 5S Subshell Of Xenon: A Multichannel K-Matrix Calculation Including Spin-Orbit Interactions, Keh-Ning Huang, Anthony F. Starace
Photoionization Of The 5S Subshell Of Xenon: A Multichannel K-Matrix Calculation Including Spin-Orbit Interactions, Keh-Ning Huang, Anthony F. Starace
Anthony F. Starace Publications
Ab initio theoretical calculations are presented for the cross section, angular distribution, and spin polarization of photoelectrons for the 5s subshell of xenon. Starting from an initial basis of nonrelativistic Hartree-Fock wave functions, the authors treat the effect of final-state spin-orbit interaction in the Breit-Pauli approximation exactly. Electrostatic correlations between the 5s and 5p subshells are also included. Good agreement is obtained with experiment in the case of the photoionization cross section, but only qualitative agreement with experiment and with other theoretical calculations is obtained in the case of the photoelectron angular distribution due to the difficulty …
A Graphical Method For Calculating First Order Transition Matrices For Open-Shell Atoms In The Random Phase Approximation, Anthony F. Starace, Siamak Shahabi
A Graphical Method For Calculating First Order Transition Matrices For Open-Shell Atoms In The Random Phase Approximation, Anthony F. Starace, Siamak Shahabi
Anthony F. Starace Publications
A graphical procedure is presented for calculating first order transition matrices for a general (open-shell) atom. The first order transition matrix may be used to calculate matrix elements of a general one-body operator of rank λ in orbital space and σ in spin space. In the random phase approximation we obtain a set of N + N′ coupled differential equations for N final state radial functions and N′ initial state radial functions which completely determine the first order transition matrix for an atomic system having N final state channels. (The relation of N′ to N is dependent on the atomic …