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Full-Text Articles in Physics

Short-Pulse Laser-Induced Stabilization Of Autoionizing States, Heider N. Ereifej, J. Greg Story Sep 2000

Short-Pulse Laser-Induced Stabilization Of Autoionizing States, Heider N. Ereifej, J. Greg Story

Physics Faculty Research & Creative Works

Atoms in doubly excited states above the first ionization limit can decay via autoionization in which an electron is emitted leaving an ion, or by photoemission which leaves the atom in a singly excited state. In this paper, it is demonstrated that interaction between the atoms and a laser pulse that is short compared to the autoionization lifetime can lead to large enhancement of the photoemission process by stimulating the atoms to emit a photon. Since the resultant singly excited atoms do not autoionize, this process can be viewed as an enhancement of the stabilization of the doubly excited atoms …


Direct Measurement Of Oscillations Between Degenerate Two-Electron Bound-State Configurations In A Rapidly Autoionizing System, Heider N. Ereifej, J. Greg Story Jul 2000

Direct Measurement Of Oscillations Between Degenerate Two-Electron Bound-State Configurations In A Rapidly Autoionizing System, Heider N. Ereifej, J. Greg Story

Physics Faculty Research & Creative Works

In this paper we report a direct observation of the oscillation between bound-state configurations in a rapidly autoionizing system. Calcium atoms were excited to a pure 4p3/2nd two-electron configuration using a 500-fsec laser pulse. The initial 4p3/2nd doubly excited state is energy degenerate with the 4p1/2n'd states and several continuum channels. Because of the short-pulse excitation, the initial state of the atom is not an energy eigenstate, but a nonstationary wave packet. As a result, oscillations between the two bound configurations were produced. These oscillations were measured by scanning the timing of a second …


Mirroring And Mimicking Of Partial Cross Sections In The Vicinity Of A Resonance, Chien-Nan Liu, Anthony F. Starace Jan 2000

Mirroring And Mimicking Of Partial Cross Sections In The Vicinity Of A Resonance, Chien-Nan Liu, Anthony F. Starace

Anthony F. Starace Publications

We review recent analytical work on mirroring and mimicking behavior of resonance profiles in different partial cross sections. This work is related to the work of Fano and Cooper on resonance profiles in total cross sections and that of Starace on resonance profiles in partial cross sections. Applications of the new theories (describing mirroring and mimicking behavior) to recent experimental measurements and theoretical predictions for photoionization, photodetachment, and Auger spectroscopy in the vicinity of resonance structures are discussed.