Results 151 to 160 of about 802,471 (226)

Determination of Positronium – Atom Collision Cross Section

Canadian Journal of Physics, 1975
We have determined the collision cross section of positronium in He, Ne, Ar, Kr, Xe, N2, and isobutane gases at thermal energies by studying the diffusion of positronium to the walls of a specially designed chamber. The time distribution of annihilations is measured as a function of pressure for each gas.
D. M. Spektor, D. A. L. Paul
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Photoionization cross sections for atomic oxygen

Planetary and Space Science, 1967
Abstract Photoionization cross sections for ground state atomic oxygen are presented for wavelengths longer than 25 A. Multi-channel expressions, in the dipole approximation, are used to calculate cross sections for the ejection of an outer subshell electron.
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Spin-change cross sections between hydrogen atoms

Proceedings of the Physical Society, 1964
The quantal formula for spin change in the collision of a pair of hydrogen atoms is evaluated at temperatures up to 1000 °K. Good agreement is obtained at temperature greater than 10 °K with the semi-classical calculations of Smith.
A Dalgarno, R J W Henry
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Analytical ionization cross sections for atomic collisions

The Journal of Chemical Physics, 1991
General analytical expressions for cross sections for direct ionization in atom–atom collisions are evaluated using the classical impulse approximation. The approach is also applied to ion–atom and molecule–molecule interactions. The overall accuracy of the obtained cross sections in a broad range of energy is better, when compared with existing ...
J. A. Kunc, W. H. Soon
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Electron impact ionization cross sections of atoms

Canadian Journal of Physics, 2015
In this article, we report the electron impact ionization cross sections for atoms Si, P, S, Sc, Cr, Mn, Co, Zn, Ga, Ge, Nb, Rh, and Cd, having applications in different areas of applied science and technology. The energy regime for the calculation is from the ionization threshold of the target to 2000 eV.
Jaspreet Kaur, Dhanoj Gupta, Rahla Naghma, Debdeep Ghoshal, Bobby Antony   +4 more
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Electron-impact cross sections of atomic oxygen

Journal of Physics B: Atomic, Molecular and Optical Physics, 2003
We report electron-impact-induced emission cross sections for the 2p4 3P–3s 3So (130.4 nm), 2p4 3P–3d 3Do (102.7 nm), 2p4 3P–3s' 3Do (98.9 nm) and 2p4 3P–3s'' 3Po (87.8 nm) transitions of atomic oxygen. Measurements were made using a magnetically confined electron beam in collision with atomic oxygen produced by an extended microwave discharge source ...
P V Johnson, I Kanik, D E Shemansky, X Liu   +3 more
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Photoionization cross-section calculations for atomic lithium

Journal of Electron Spectroscopy and Related Phenomena, 1990
Calculations based upon relaxed Hartree-Fock functions for the 1s diagram and satellite photoionization cross sections for atomic lithium are presented and compared with current experimental results. Configuration interaction in the initial and final ionic-core states is included in the calculation.
G.B. Armen, B.I. Craig, P.P. Larkins, J.A. Richards   +3 more
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Calculation of Atom–Atom Excitation Cross Sections by Classical Methods

The Journal of Chemical Physics, 1969
Atom-atom collisional excitation cross sections obtained from ionization cross sections, noting Thomson classical ...
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Measurement of atomic differential scattering cross-sections

British Journal of Applied Physics, 1960
The derivation of the atomic differential scattering cross-section (dσT/dω)θ from the intensity distribution in the background of electron diffraction patterns is discussed, bearing in mind the possible effects of plural scattering. It is shown that the variation of (dσT/dω)θ with specimen thickness reported by Haine and Agar is not real but appeared ...
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Analytical total photo cross section for atoms

Journal of Physics B: Atomic, Molecular and Optical Physics, 1995
A quantum-classical approximation for the total photo cross section of many-electron atoms is derived in a time-dependent formulation. Exact commutator relations for the time-dependent dipole operator and a classical approximation for the propagator are used. Analytical expressions are derived for one- and two-electron atoms. We compare the results for
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