Theoretical photoionization partial cross sections and angular distribution parameters of doubly excited helium

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

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Angular distribution parameters in two-photon double ionization of helium beyond the dipole approximation

Physical Review A ◽

10.1103/physreva.105.013104 ◽

2022 ◽

Vol 105 (1) ◽

Author(s):

Yong-Kang Fang ◽

Hao Liang ◽

Wei-Chao Jiang ◽

Liang-You Peng

Keyword(s):

Angular Distribution ◽

Dipole Approximation ◽

Double Ionization ◽

Two Photon ◽

Distribution Parameters

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Ab initiocalculations of perturbed core-excited resonances in H2associated with H ,n=3: analogies and differences with doubly-excited helium

Molecular Physics ◽

10.1080/00268970500358776 ◽

2006 ◽

Vol 104 (1) ◽

pp. 187-196 ◽

Cited By ~ 5

Author(s):

H. Oueslati ◽

M. Telmini ◽

CH. Jungen

Keyword(s):

Doubly Excited ◽

Excited Helium

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Laser-induced Compton scattering from a bound electron

Canadian Journal of Physics ◽

10.1139/p92-007 ◽

1992 ◽

Vol 70 (1) ◽

pp. 72-77 ◽

Cited By ~ 4

Author(s):

F. Ehlotzky

Keyword(s):

Angular Distribution ◽

Compton Scattering ◽

Harmonic Generation ◽

Cross Sections ◽

Laser Field ◽

Multiphoton Ionization ◽

Ionization Threshold ◽

Powerful Laser ◽

Bound Electrons ◽

Bound Electron

We investigate nonrelativistically Compton scattering by an electron bound in hydrogen in a powerful laser field. The corresponding nonlinear rates and cross sections are evaluated in a Keldysh-type of approximation and compared with the rates and cross sections of multiphoton ionization and harmonic generation. We find that multiphoton ionization overshadows Compton scattering by many orders of magnitude, however, Compton scattering may well compete with harmonic generation above the ionization threshold, since, in particular, both processes have the same angular distribution and only odd harmonics can be created by bound electrons, while in bound-free Compton scattering all harmonics will be generated.

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MEASUREMENT OF FISSION FRAGMENT ANISOTROPIES FOR PROTON-INDUCED FISSION OF TWO PRE-ACTINIDE NUCLEI AT SEVERAL ENERGIES

International Journal of Modern Physics A ◽

10.1142/s0217751x07034428 ◽

2007 ◽

Vol 22 (05) ◽

pp. 1027-1037 ◽

Cited By ~ 2

Author(s):

S. SOHEYLI ◽

H. NOSHAD ◽

M. LAMEHI-RACHTI

Keyword(s):

Angular Distribution ◽

Statistical Model ◽

Cross Sections ◽

Fission Fragment ◽

Anomalous Behavior ◽

Surface Barrier ◽

Mass Asymmetry ◽

Fission Fragments ◽

Induced Fission ◽

Barrier Detectors

The angular distribution of fission fragments has been measured for proton-induced fission of 197 Au and 209 Bi nuclei at several energies between 25 and 30 MeV using surface-barrier detectors. The measured anisotropies are found to be in agreement with the predictions of the standard saddle-point statistical model. The measured anisotropies for neither of the nuclei show any anomalous behavior as a function of both energy and entrance channel mass asymmetry. The fission cross sections of 197 Au and 209 Bi nuclei were also measured and compared with that of the previous works.

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