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[en] A parameterization is provided for the bremsstrahlung spectrum in the incident electron energy range 10 to 500 keV for all elements, with particular emphasis on the range 20 to 100 keV for Z = 41 to 92. A general accuracy of 20% is achieved, with 50% in the worst cases, in most ranges utilizing simple one variable functions

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[en] A tabulation is presented for the amplitudes and differential cross sections for Rayleigh scattering from neon and carbon in the energy range from 100 eV to 30 keV, at 5⁰ intervals. At these energies Rayleigh scattering gives the only significant contribution to the total elastic scattering differential cross section for photon-atom scattering. The amplitudes and cross sections can now be calculated to better than 1% for all energies between 0.1 keV and 10 MeV. 7 references

[en] Electron ion bremsstrahlung cross sections β² divided-by hν d²σ(hν,1/2 mv², θ)divided-by d(hν) d(θ) are evaluated for the fixed photon emission angle θ=90 degrees, as relevant to experiments where the spectra are recorded perpendicularly to the electron trajectories. For a fixed photon energy hν, the cross sections in the mildly relativistic regime are varying only very slowly with the incident electron energy 1/2 mv² (contrary to the angular integrated cross section). Energy ranges and examples for which this property is found are indicated. As an application, we show how this enables more detailed and more rigorous interpretations of bremsstrahlung spectra

[en] When photon energies are well below 1 MeV the only significant contribution to elastic (coherent) photon-atom scattering comes from Rayleigh scattering, the elastic scattering of photons from bound atomic electrons. This report discusses the Rayleigh scattering cross sections for atoms and ions of low nuclear charge, particularly for photon energies in the vicinity of the threshold for photoionization from the K-shell. Just below this threshold energy there is a sequence of resonances in the elastic scattering amplitude. Each resonance occurs at an energy corresponding to the excitation of a K-shell electron to a higher unfilled shell. For a multi-electron atom the total cross section can go through a near zero minimum just below the resonance region due to interference between K and L amplitudes. The resonance region expands with increasing ionization, on the low side as more interior shells become unfilled and accessible, and, on the high side as the ionization threshold increases. Above the ionization threshold, in an isonuclear sequence the K-shell amplitudes share a common curve differing only in the position of the threshold. When the K-shell is opened the amplitude departs from this common curve. Above, but near, threshold the imaginary part of the K-shell amplitude is important but it rapidly decreases. Well above the threshold form factor predictions are approached for the atom and for the scattering from each subshell separately

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[en] The current status of Compton scattering, both experimental observations and the theoretical predictions, is examined. Classes of experiments are distinguished and the results obtained are summarized. The validity of the incoherent scattering function approximation and the impulse approximation is discussed. These simple theoretical approaches are compared with predictions of the nonrelativistic dipole formula of Gavrila and with the relativistic results of Whittingham. It is noted that the A^-2 based approximations fail to predict resonances and an infrared divergence, both of which have been observed. It appears that at present the various available theoretical approaches differ significantly in their predictions and that further and more systematic work is required

[en] In this discussion of photon scattering from atoms, we distinguish between elastic and inelastic scattering, and we restrict our attention to the scattering of one photon from an isolated atom. We do not consider the absorption of that photon (atomic photoeffect), or multi-photon processes (as in an intense laser beam), or processes in which additional particles are created (as in photon splitting or creation of electron-positron pairs), or effects of atomic environments (as in solids or plasmas). We also do not consider two-step processes involving substantial time delays, which can be understood in terms of absorption and subsequent re-emission (fluorescence)