Results 261 to 270 of about 6,394,824 (315)

Photoionization cross sections of atomic ions

Journal of Electron Spectroscopy and Related Phenomena, 2002
Abstract Experimental techniques for photoionisation measurements on atomic ions are described, and recent progress in the measurement of absolute photoionisation cross sections is reviewed. The complementary contributions of the two main experimental methods, merged beam and dual laser produced plasma (DLPP), pointing out both the problems and ...
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Maximum Ionization Cross Section of Atoms

The Journal of Chemical Physics, 1969
Various theoretical approaches for estimation of maximum ionization cross sections have been discussed and three new relations have been developed and used to evaluate maximum cross sections. Mann's calculations have been critically examined, and the present results have been compared with available experimental results.
Prabhakar Tiwari, D. K. Rai, M. L. Rustgi   +2 more
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On atomic photoionization cross section calculation

Physics Letters A, 1969
Abstract Essential peculiarities of the Hartree-Fock photoionization cross section are discussed: 1) the choice of the operator of interaction with the electromagnetic field, 2) sum rules and 3) the influence of various modifications of the self-consistent field.
M.Ya. Amusia, N.A. Cherepkov, L.V. Chernysheva, S.I. Sheftel   +3 more
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Electron Ionization Cross Sections for Atomic Subshells

Microscopy and Microanalysis, 2003
Ionization of atoms is the first step in many analytical procedures. The cross section for ionizing a particular atomic shell is essential for calculating the magnitude of analytical signals. Calculations using atomic wave functions for various shells of all elements relevant for X-ray microanalysis over a range of electron energies up to 400 keV ...
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Total atomic photoelectric cross-sections

Il Nuovo Cimento B Series 10, 1969
Total atomic photoelectric cross-sections have been obtained by the subtraction technique for the elements Cu, Mo, Ag, Sn, W, Au, Pb and U in the energy region 20 to 1330 keV; and compared with the tabulated theoretical predictions of Schmickley and Pratt. It has been found that, in general, there is satisfactory agreement between the two.
K. Parthasaradhi, S. Ramamurty
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Photoionization cross-sections for atomic oxygen

Planetary and Space Science, 1992
Abstract The R-matrix method is used to obtain cross-sections for the photoionization of atomic oxygen from the 2s22p43P state of O to the 2s22p34So, 2Do, 2Po and 2s2p44P, 2P states of O+. Ea for the 4So and the 2Do O+ states are shown to be reliable but the present results reveal considerable discrepancies for the other final ion states, in ...
K.L. Bell, R.P. Stafford
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Rydberg-atom-Rydberg-atom ionisation cross sections

Journal of Physics B: Atomic and Molecular Physics, 1979
A four-body classical-trajectory Monte Carlo method has been applied to Rydberg-atom-Rydberg-atom scattering problems. Numerical calculations were conducted over the velocity range ve/3 to 3v2 where v2(au)=1/n and n is the principal quantum number of the Rydberg atom.
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Aggregates of atoms and their stopping cross sections

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1985
Abstract The problem of deriving universal atomic stopping cross sections from measurements performed in real physical targets is discussed with regard to the influence of the bonds on the stopping cross sections, which exists whenever atoms join to form molecules or a solid. This influence has to be considered for all investigated substances, except
Wolfgang Neuwirth, Georg Both
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Atomic Photoionization Cross Sections

1978
In these lectures I will discuss various methods of calculating atomic photoionization cross sections with emphasis on resonant structures. I will attempt to order the methods according to the complexity of the problem that they can be used on. Thus the Feshbach projection operator formalism, which is most applicable to the calculation of resonance ...
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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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