Double Photoionization of Endohedrally Confined Atoms

Abstract

We study the double electronic emission by photon impact from ground state of two-electron atoms in the center of a model spherical fullerene, which is described by a square-well shell. Cross-sections for different well depth are computed within a separable model for the final state, and a configuration interaction state for the initial one. Triple differential cross-sections show a strong dependence on the well depth and on the energy of the emitted electrons, due to the delocalization of the electrons in the initial state. The fullerene potential also allows higher angular momenta partial waves to be included in the process, which modifies the well-known two-lobe cross-section from isolated atom.

Single photoionization with excitation and double photoionization of He@C36, He@C60and He@C82

“…Akin to the single photoionization process in endofullerenes, confinement resonance structure has also been predicted to occur in the double photoionization cross section [14][15][16][17]. However, the related two-electron process of single photoionization with excitation in which one of the atomic electrons is ejected into the continuum while the other is excited to a bound state n of the atomic ion, to the best of our knowledge, has not been considered.…”

“…In order to keep the analysis simple, we adopt a spherical shell potential to represent the C N fullerene, using input from experiments where available, with the confined atom treated using the two-electron time-dependent close-coupling (TDCC) method [18]. The TDCC method has been used to study the double photoionization of He confined in both neutral and charged C 60 [15][16][17]. The method expands the electronic wavefunction in coupled spherical harmonics for each total orbital angular momentum, L, and total spin angular momentum, S. By propagating the two-electron wavefunction in time on a numerical lattice, cross sections of interest may be extracted by projections of the final time wavefunction.…”

Spectral properties of endohedrally confined helium atom

“…Meanwhile, some researchers have done some experiments on the spectral properties of endohedrally confined atoms. [18][19][20][21][22][23] In our work, a B-spline functions [24] method is applied to calculate the energy level and the dipole oscillator strength of endohedrally confined helium, when the square potential well is changed into a parabolic potential one. The causes of the "mirror collapse" and "giant resonance" phenomena are analyzed.…”