9 research outputs found

    Correlation structure in nondipole photoionization

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    The nondipole parameters that characterize the angular disribution of the photoelectrons from the 3d subshell of Cs are found to be altered qualitatively by the inclusion of correlation in the form of interchannel coupling between the 3d3/23d_{3/2} and 3d5/23d_{5/2} photoionization channels. A prominent characteristic maximum is predicted only in the parameters for 3d5/23d_{5/2} photoionization, while the effect for 3d3/23d_{3/2} is rather weak. The results are obtained within the framework of the Generalized Random Phase Approximation with Exchange (GRPAE), which in addition to the RPAE effects takes into account the rearrangement of all atomic electrons due to the creation of a 3d vacancy

    Superluminal source of directional pulsed wideband electromagnetic radiation

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    A photoemission source of directional pulsed wideband electromagnetic radiation in the microwave region is developed, and the time profile of the generated pulse is investigated. The source is a vacuum photodiode of a parabolic shape in which a Cherenkov radiation pulse is formed by an electron current wave excited by an incident laser pulse and propagating along the surface of the anode mesh with a phase velocity higher than the speed of light. © 2014, Allerton Press, Inc

    Superluminal source of directional pulsed wideband electromagnetic radiation

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    A photoemission source of directional pulsed wideband electromagnetic radiation in the microwave region is developed, and the time profile of the generated pulse is investigated. The source is a vacuum photodiode of a parabolic shape in which a Cherenkov radiation pulse is formed by an electron current wave excited by an incident laser pulse and propagating along the surface of the anode mesh with a phase velocity higher than the speed of light. © 2014, Allerton Press, Inc

    Valence photoionization of small alkaline earth atoms endohedrally confined in C60\mathrm{C_{60}}

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    A theoretical study of photoionization from the outermost orbitals of Be, Mg and Ca atoms endohedrally confined in C60 is reported. The fullerene ion core, comprised of sixty C4+, is smudged into a continuous jellium charge distribution, while the delocalized cloud of carbon valence electrons plus the encaged atom are treated in the time-dependent local density approximation (TDLDA). Systematic evolution of the mixing of outer atomic level with states of the C60 valence band is found along the sequence. This is found to influence the plasmonic enhancement of atomic photoionization at low energies and the geometry-revealing confinement oscillations at high energies in significantly different ways: (a) the extent of enhancement is mainly determined by the strength of atomic ionization, giving the strongest enhancement for Be even though Ca suffers the largest mixing. But (b) strongest collateral oscillations are uncovered for Ca, since, relative to Be and Mg, the mixing causes the highest photoelectron production at confining boundaries of Ca. The study paints the first comparative picture of the atomic valence photospectra for alkaline earth metallofullerenes in a dynamical many-electron framework
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