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We discuss the temporal picture of electron collisions with fullerene. Within the framework of a Dirac bubble potential model for the fullerene shell, we calculate the time delay in slow-electron elastic scattering by it. It appeared that the time of transmission of an electron wave packet through the Dirac bubble potential sphere that simulates a real potential of the C60 reaches up to 104 attoseconds. Resonances in the time delays are due to the temporary trapping of electron into quasi-bound states before it leaves the interaction region. As concrete targets we choose almost ideally spherical endohedrals C20, C60, C72, and C80. We present dependences of time-delay upon collision energy.
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Within the framework of a Dirac bubble potential model for the C60 fullerene shell, we calculated the time delay in slow-electron elastic scattering by C60. It appeared that the time of transmission of an electron wave packet through the Dirac bubble potential sphere that simulates a real potential of the C60 cage exceeds by more than an order of magnitude the transmission time via a single atomic core. Resonances in the time delays are due to the temporary trapping of electron into quasi-bound states before it leaves the interaction region.
Electrons released from clusters through strong Xray pulses show broad kinetic-energy spectra, extending from the atomic excess energy down to the threshold, where usually a strong peak appears. These low-energy electrons are normally attributed to evaporation from the nano-plasma formed in the highly-charged clusters. Here, it is shown that also directly emitted photo electrons generate a pronounced spectral feature close to threshold. Furthermore, we give an analytical approximation for the direct photo-electron spectrum.
In this Letter, we investigate the time delay of photoelectrons by fullerenes shell in endohedrals. We present general formulas in the frame of the random phase approximation with exchange (RPAE) applied to endohedrals A@CN that consist of an atom A located inside of a fullerenes shell constructed of N carbon atoms C. We calculate the time delay of electrons that leave the inner atom A in course of A@CN photoionization. Our aim is to clarify the role that is played by CN shell. As concrete examples of A we have considered Ne, Fr, Kr and Xe, and as fullerene we consider C60. The presence of the C60 shell manifests itself in powerful oscillations of the time delay of an electron that is ionized from a given subshell nl by a photon with energy. Calculations are performed for outer, subvalent and d-subshells.
We have calculated partial contributions of different endohedral and atomic subshells to the total dipole sum rule in the frame of the random phase approximation with exchange (RPAE) and found that they are essentially different from the numbers of electrons in respective subshells. This difference manifests the strength of the intershell interaction. We present concrete results of calculations for endohedrals, composed of fullerene C60 and all noble gases He, Ne, Ar, Kr and Xe thus forming respectively He@C60, Ne@C60, Ar@C60, Kr@C60, and Xe@C60. For comparison we obtained similar results for isolated noble gas atoms. The deviation from number of electrons in outer subshells proved to be much bigger in endohedrals than in isolated atoms thus demonstrating considerably stronger intershell correlations there.
In this paper we calculate the elastic scattering cross sections of slow electron by carbon nanotubes. The corresponding electron-nanotube interaction is substituted by a zero-thickness cylindrical potential that neglects the atomic structure of real nanotubes, thus limiting the range of applicability of our approach to sufficiently low incoming electron energies. The strength of the potential is chosen the same that was used in describing scattering of electrons by fullerene C60. We present results for total and partial electron scattering cross sections as well as respective angular distributions, all with account of five lowest angular momenta contributions. In the calculations we assumed that the incoming electron moves perpendicular to the nanotube axis, since along the axis the incoming electron moves freely.
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