Electron impact cross sections and spatial aspects of electron energy degradation in water vapor

1986 ◽  
Vol 30 (S20) ◽  
pp. 547-554 ◽  
Author(s):  
Dayashankar ◽  
Suk T. Suh ◽  
A. E. S. Green
Keyword(s):  
Water Vapor ◽  
Electron Impact ◽  
Electron Energy ◽  
Cross Sections ◽  
Energy Degradation

scholarly journals Electron Impact Excitation of Extreme Ultra-Violet Transitions in Xe7+ – Xe10+ Ions

Atoms ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 76
Author(s):  
Aloka Kumar Sahoo ◽  
Lalita Sharma
Keyword(s):  
Electron Impact ◽  
Electron Energy ◽  
Cross Sections ◽  
Energy Levels ◽  
Ultra Violet ◽  
High Energy ◽  
Impact Excitation ◽  
Rate Coefficients ◽  
Electron Impact Excitation ◽  
Excitation Threshold

In the present work, a detailed study on the electron impact excitation of Xe7+, Xe8+, Xe9+ and Xe10+ ions for the dipole allowed (E1) transitions in the EUV range of 8–19 nm is presented. The multi-configuration Dirac–Fock method is used for the atomic structure calculation including the Breit and QED corrections along with the relativistic configuration interaction approach. We have compared our calculated energy levels, wavelengths and transition rates with other reported experimental and theoretical results. Further, the relativistic distorted wave method is used to calculate the cross sections from the excitation threshold to 3000 eV electron energy. For plasma physics applications, we have reported the fitting parameters of these cross sections using two different formulae for low and high energy ranges. The rate coefficients are also obtained using our calculated cross sections and considering the Maxwellian electron energy distribution function in the electron temperature range from 5 eV to 100 eV.

Absolute vibrational differential cross sections of water vapor by 30 and 50 eV electron impact

1991 ◽  
Vol 95 (3) ◽  
pp. 1671-1675 ◽  
Author(s):  
M. Furlan ◽  
M.‐J. Hubin‐Franskin ◽  
J. Delwiche ◽  
J. E. Collin
Keyword(s):  
Water Vapor ◽  
Electron Impact ◽  
Cross Sections ◽  
Differential Cross ◽  
Differential Cross Sections

scholarly journals Прямое диссоциативное возбуждение гетероядерных и гомоядерных ионов инертных газов электронным ударом

2020 ◽  
Vol 128 (11) ◽  
pp. 1596
Author(s):  
К.С. Кислов ◽  
А.А. Нариц ◽  
В.С. Лебедев
Keyword(s):  
Electron Impact ◽  
Electron Energy ◽  
Cross Sections ◽  
Rate Constants ◽  
Strong Dependence ◽  
Molecular Ions ◽  
Inert Gases ◽  
Dissociative Excitation ◽  
Differential Rate ◽  
Molecular Ion

A theoretical description of the process of dissociative excitation of a molecular ion by electron impact in the case of effective population of a huge number of its vibrational-rotational levels is presented. Our consideration is based on the quantal version of the theory of non-adiabatic transitions between the electronic terms of a molecular ion combined with replacing the summation over vJ-levels by integration over v and J. Semianalytical formulas are derived for the integral contribution of the entire vibrational-rotational quasicontinuum to the cross sections, $\sigma_T^{\mathrm{de}}(\varepsilon)$, and the rate constants, $\alpha^{\mathrm{de}}(T, T_e)$ of the process under study in a plasma with temperatures $T_e$ and $T$ of its electronic and ionic components. The developed theory is used to study the processes of dissociative excitation of heteronuclear (HeXe$^{+}$ and ArXe$^{+}$) and homonuclear (Ar$_2^{+}$ and Xe$_2^{+}$) ions of inert gases. We demonstrate a strong dependence of the results on the ion dissociation energy and large differences in the behavior and characteristic values of $\sigma_T^{\mathrm{de}}(\varepsilon)$ and $\alpha^{\mathrm{de}}(T, T_e)$ for these systems in different ranges of electron energy, $\varepsilon$, and temperatures $T_e$ and $T$. The regions of dominance of the contributions of two competing channels are determined: direct dissociative excitation and dissociative recombination into total cross sections and the rate constants of destruction of rare gas molecular ions by electron impact. Analyzing behavior of the differential rate constants of dissociative excitation per unit range of electron energy in the final channel of reaction we demonstrate qualitative differences in the dynamics of this process for weakly bound and moderately bound molecular ions.

The measurement of inner-shell ionization cross aections by electron impact in a TEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1266-1267
Author(s):  
Raynald Gauvin ◽  
Gilles L'Espérance
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Weight Fraction ◽  
Thin Foil ◽  
Specimen Thickness ◽  
Ionization Cross ◽  
Electron Dose ◽  
Total Electron ◽  
Inner Shell Ionization ◽  
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. In this work, the results of the measurement of inner-shell ionization cross-sections by electron impact, Q, in a TEM are presented for the K shell.The measurement of QNi has been performed at 120 KeV in a TEM by measuring the net X-ray intensity of the Kα line of Ni, INi, which is related to QNi by the relation :(1)where i is the total electron dose, (Ω/4π)is the fractional solid angle, ω is the fluorescence yield, α is the relative intensity factor, ε is the Si (Li) detector efficiency, A is the atomic weight, ρ is the sample density, No is Avogadro's number, t' is the distance traveled by the electrons in the specimen which is equal to τ sec θ neglecting beam broadening where τ is the specimen thickness and θ is the angle between the electron beam and the normal of the thin foil and CNi is the weight fraction of Ni.

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