Feasibility study of thin films deposited on a self-supporting carbon grid substrate target on the measurement of atomic inner-shell ionization cross-sections impacted by 3–30 keV electrons

The ECPSSR theory to calculate the inner-shell ionization cross sections by light-ion impact is studied. Starting from the general formulation of the plane-wave Born approximation, the corrections for the energy-loss effect (E) and the Coulomb-deflection effect (C) of the projectile, and for the binding-polarization effect in the perturbed-stationary-state approach (PSS) and the electronic relativistic effect (R) of the target electron are described. The calculated values in the ECPSSR theory are compared with the experimental data. In general, agreement is good, but there are systematic deviations for low-energy projectiles. The comparison with other theoretical treatments for the inner-shell ionization is discussed.

Download Full-text

New Measurements and Calculations of Inner-shell Ionization Cross Sections by Electron Impact

Microscopy and Microanalysis ◽

10.1017/s1431927606064907 ◽

2006 ◽

Vol 12 (S02) ◽

pp. 844-845

Author(s):

X Llovet ◽

C Merlet ◽

D Bote ◽

JM Fernández-Varea ◽

F Salvat

Keyword(s):

Electron Impact ◽

Cross Sections ◽

Ionization Cross ◽

Inner Shell Ionization ◽

Ionization Cross Sections ◽

Shell Ionization

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006

Download Full-text

Inner-Shell Ionization Cross Sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010013362x ◽

1990 ◽

Vol 48 (2) ◽

pp. 6-7

Author(s):

C. J. Powell

Keyword(s):

Cross Section ◽

Cross Sections ◽

Relativistic Correction ◽

Bethe Equation ◽

Ionization Cross ◽

Section Data ◽

Inner Shell Ionization ◽

Ionization Cross Sections ◽

Image Position ◽

Shell Ionization

Values of cross sections for ionization of inner-shell electrons by electron impact are required for electron probe microanalysis, Auger-electron spectroscopy, and electron energy-loss spectroscopy. The present author has reviewed measurements and calculations of inner-shell ionization cross sections. This paper is an update and summary of these previous reviews.It is convenient to start with the Bethe equation for inner-shell ionization cross sections which is frequently used (and misused) in x-ray microanalysis:(1)where σnℓ is the cross section for ionization of the nℓ shell with binding energy Enℓ by incident electrons of energy E. The terms bnℓ and cnℓ are the Bethe parameters discussed further below. It has been assumed in the derivation of Eq. (1) that E ≫ Enℓ ; this requirement will also be discussed. Finally, it has been assumed here that E is low enough (≲50 keV) so that a relativistic correction is unnecessary.The extent to which a given set of measured or calculated cross-section data is consistent with Eq. (1) can be determined from a Fano plot in which σnℓE is plotted versus ℓnE; if such a plot is linear, Eq. (1) is consistent with the data and values of the Bethe parameters can be easily derived.

Download Full-text