A COMPARISON OF THIN AND THICK TARGET METHODS OF MEASURING PROTON-INDUCED K-SHELL IONIZATION CROSS-SECTIONS

1980 ◽  
pp. 131-138
Author(s):  
K.M. BARFOOT ◽  
I.V. MITCHELL ◽  
H.L. ESCHBACH ◽  
W.B. GILBOY
Keyword(s):  
Cross Sections ◽  
Thick Target ◽  
Ionization Cross ◽  
Ionization Cross Sections ◽  
Shell Ionization

Measurements of K-shell ionization cross sections of Fe, Ni, and Zn by 7–29 keV electron impact using the thick-target method

2020 ◽  
Vol 98 (10) ◽  
pp. 970-975
Author(s):  
L.X. Tian ◽  
C.C. Dai ◽  
Y.J. Liu
Keyword(s):  
Experimental Data ◽  
Electron Impact ◽  
Cross Sections ◽  
Thick Target ◽  
Tikhonov Regularization Method ◽  
Ionization Cross ◽  
Bremsstrahlung Photons ◽  
Ill Posed ◽  
Ionization Cross Sections ◽  
Shell Ionization

The measurements of K-shell ionization cross sections for Fe, Ni, and Zn were performed using 7–29 keV electron impact on thick targets. Monte Carlo simulations were employed to correct the effects due to the multiple-scattered electrons and bremsstrahlung photons as well as other secondary particles within the thick targets. The so-called Tikhonov regularization method was adopted to deal with the ill-posed inverse problem involved in the thick-target method. The experimental results were compared with the DWBA and PWBA-C-Ex predictions as well as existing experimental data from the literature. It is observed that our experimental data are in better agreement with the theoretical results based on the DWBA model developed by Bote et al.

Relative Variation of K- And L-Shell Ionization Cross Sections by Electron Impact

1999 ◽  
Vol 5 (S2) ◽  
pp. 584-585
Author(s):  
X. Llovet ◽  
C. Merlet ◽  
J.M. Fernández-Varea ◽  
F. Salvat
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Carbon Films ◽  
X Rays ◽  
Empirical Formulas ◽  
Relative Variation ◽  
Ionization Cross ◽  
Ionization Cross Sections ◽  
Semi Empirical ◽  
Shell Ionization

Knowledge of inner-shell ionization cross sections by electron impact is needed for quantitative procedures in electron probe microanalysis (EPMA) and Auger electron spectroscopy (AES) The common practice is to use semi-empirical formulas, based on the asymptotic limit of the Bethe theory, which sometimes are used beyond their domain of validity. Experimental measurements of ionization cross sections are scarce and affected by considerable uncertainties, thus a mere comparison with experimental data does not permit to draw a definite conclusion abou the accuracy of the various formulas. In this communication, we present new measurements o the relative variation of K- and L-shell ionization cross sections deduced from the counting rate of characteristic x-rays emitted by extremely thin films of Cr, Ni, Cu, Te, Au and Bi bombardec by keV electrons.The studied films were produced by thermal evaporation on backing self-supported 30 nm carbon films.

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