Cross sections for electron collisions with H2O: elastic scattering and electronic excitation for the ã3B1and Ã1B1states

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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Information and Dose in the Scanning Transmission Ion Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001021 ◽

1980 ◽

Vol 38 ◽

pp. 232-233

Author(s):

Fox T. R. ◽

R. Levi-Setti

Keyword(s):

Information Retrieval ◽

Electron Microscope ◽

Elastic Scattering ◽

Energy Loss ◽

Cross Sections ◽

Previous Analysis ◽

Single Scattering ◽

Screening Length ◽

Relative Damage ◽

Scanning Transmission

At an earlier meeting [1], we discussed information retrieval in the scanning transmission ion microscope (STIM) compared with the electron microscope at the same energy. We treated elastic scattering contrast, using total elastic cross sections; relative damage was estimated from energy loss data. This treatment is valid for “thin” specimens, where the incident particles suffer only single scattering. Since proton cross sections exceed electron cross sections, a given specimen (e.g., 1 μg/cm2 of carbon at 25 keV) may be thin for electrons but “thick” for protons. Therefore, we now extend our previous analysis to include multiple scattering. Our proton results are based on the calculations of Sigmund and Winterbon [2], for 25 keV protons on carbon, using a Thomas-Fermi screened potential with a screening length of 0.0226 nm. The electron results are from Crewe and Groves [3] at 30 keV.

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A note on the relations between elastic and inelastic interactions and increasing ratio σel(s)/σtot(s) at the LHC

Modern Physics Letters A ◽

10.1142/s0217732319502596 ◽

2019 ◽

Vol 34 (32) ◽

pp. 1950259 ◽

Cited By ~ 5

Author(s):

S. M. Troshin ◽

N. E. Tyurin

Keyword(s):

Elastic Scattering ◽

Energy Dependence ◽

Impact Parameter ◽

Cross Sections ◽

Parameter Dependence ◽

Slope Parameter ◽

Short Notice ◽

Inelastic Interactions ◽

The Impact ◽

Mode A

We comment briefly on relations between the elastic and inelastic cross-sections valid for the shadow and reflective modes of the elastic scattering. Those are based on the unitarity arguments. It is shown that the redistribution of the probabilities of the elastic and inelastic interactions (the form of the inelastic overlap function becomes peripheral) under the reflective scattering mode can lead to increasing ratio of [Formula: see text] at the LHC energies. In the shadow scattering mode, the mechanism of this increase is a different one, since the impact parameter dependence of the inelastic interactions probability is central in this mode. A short notice is also given on the slope parameter and the leading contributions to its energy dependence in both modes.

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Relativistic B-Spline R-Matrix Calculations for Electron Collisions with Ytterbium

Atoms ◽

10.3390/atoms9030047 ◽

2021 ◽

Vol 9 (3) ◽

pp. 47

Author(s):

Kathryn R. Hamilton ◽

Klaus Bartschat ◽

Oleg Zatsarinny

Keyword(s):

Experimental Data ◽

Electron Scattering ◽

Cross Sections ◽

Matrix Method ◽

Model Potential ◽

Electron Collisions ◽

R Matrix ◽

B Spline ◽

Potential Approach

We have applied the full-relativistic Dirac B-Spline R-matrix method to obtain cross sections for electron scattering from ytterbium atoms. The results are compared with those obtained from a semi-relativistic (Breit-Pauli) model-potential approach and the few available experimental data.

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