Many-Body Theory of Atomic Structure and Photoionization

2013

Phys. Rev. A

We present a detailed theoretical study on the photoionization of one-and twoelectron atoms subject to external changing plasma environment based on the DebyeHückel model. Specifically, by examining the migration of the bound excited states into the continuum in the presence of plasma, our investigation has led to resonance-like photoionization structures immediately above the ionization thresholds for ,  − , and  atoms. For , unlike the usual Fano-Beutler resonances due to the configuration mixing between the doubly excited components and the singly ionization channel with different  1  2 angular momenta combination in the final state wavefunction, these plasma induced resonance-like structures result from the mixing of the quasi-bound and continuum components of the same  1  2 combination in the final state function. With a number of specific examples, we will show that the general features of these spectra could be linked directly to the overlap at small  between the effective wave functions of the outgoing ionized electron and the atomic electron in its initial states. PACS number(s); 32.80.Fb, 32.80.Gc, 32.20.Jc, 52.25.Os 1

Section: Photoionization Of One-electron Atommentioning

confidence: 99%

Section: Photoionization Of Two-electron Atommentioning

confidence: 99%

Section: Photoionization Of Two-electron Atommentioning

confidence: 99%

See 1 more Smart Citation

Atomic photoionization in a changing plasma environment

Chang

2013

Phys. Rev. A

“…The single photoionization cross section  from an initial state  to a final continuum  with an outgoing electron of momentum , using the discretized B-spline based atomic orbits, is expressed in terms of the oscillator strength   by the expression [19,20] …”

Section: Theory and Calculation Proceduresmentioning

confidence: 99%

“…The one-particle wavefunction  is calculated by expanding in terms of a set of B-splines defined between  = 0 to  = . Numerical procedure for  is detailed elsewhere [19,20].…”

Section: Theory and Calculation Proceduresmentioning

confidence: 99%

One- and two-photon ionization of hydrogen atom embedded in Debye plasmas

Chang

2013

Physics of Plasmas

We present a detailed analysis of the plasma-induced resonance-like atomic structures near the ionization threshold in one-and two-photon ionization of hydrogen atom. Such resonance-like structures result from the migration of the upper bound excited states of bound-bound atomic transitions into the continuum due to the less attractive screened Coulomb potential which simulates the external environmental effect for an atom embedded in Debye plasma. The change from the resonance-like narrow structures into broad continuous spectra as the plasma effect increases could be accounted for by the overlap between the respective wavefunctions of the atomic electron in the initial state and its corresponding outgoing ionized state in the continuum. PACS number(s); 52.25. Os, 32.80.Fb

Photoionization Profiles of Helium Autoionizing States in External DC Electric Fields

2001

J Chinese Chemical Soc

Electric‐field effects on the doubly excited resonant structures in He ground state photoionization are investigated theoretically using the complex‐rotation method with a B‐spline‐based configuration interaction (BSCI) basis. The variations of the structure profiles for the ML = 0 components of He (2,2a), (2,3 a), and (2,4a) 1P° and 1De resonance pairs for selected DC electric field strengths are examined. The changes of the resonant energies, widths, Fano q‐parameters, and back ground cross sections, are also presented.