Cross Sections for Inelastic Scattering of Electrons by Atoms - Selected Topics Related to Electron Microscopy

We begin with a resume of the Bethe theory, which provides a general framework for discussing the inelastic scattering of fast electrons and leads to powerful criteria for judging the reliability of cross-section data. The central notion of the theory is the generalized oscillator strength as a function of both the energy transfer and the momentum transfer, and is the only non-trivial factor in the inelastic-scattering cross section. Although the Bethe theory was initially conceived for free atoms, its basic ideas apply to solids, with suitable generalizations; in this respect, the notion of the dielectric response function is the most fundamental. Topics selected for discussion include the generalized oscillator strengths for the K-shell and L-shell ionization for all atoms with Z ≤ 30, evaluated by use of the Hartree-Slater potential. As a function of the energy transfer, the generalized oscillator strength most often shows a non-monotonic structure near the K-shell and L-shell thresholds, which has been interpreted as manifestations of electron-wave propagation through atomic fields. For molecules and solids, there are additional structures due to the scattering of ejected electrons by the fields of other atoms

Photoelectron angular distribution of the excited 2p^2 3p ^2S state of atomic nitrogen

Relevant data is available at: http://www.astronomy.ohio-state.edu/~nahar/nahar_radiativeatomicdata/index.htmlCalculations of the photoelectron angular distribution asymmetry parameter ß for the excited 2p^2 3p ^2S state of atomic nitrogen have been performed using Hartree-Fock discrete and continuum wave functions with relaxation. The results show reasonably good agreement with a recent measurement of ß at a single energy.The work was supported by the U.S. Army Research Office and the National Science Foundation

Photoionization of the 7d excited state of cesium

Relevant data is available at: http://www.astronomy.ohio-state.edu/~nahar/nahar_radiativeatomicdata/index.htmlThe photoionization cross section for the excited 7d state of atomic cesium has been calculated in the Hartree-Fock approximation. The results show excellent agreement with a recent measurement.This work was supported by the U.S. Army Research Office and the National Science Foundation

Fuel cycles in nuclear reactors

Series numbering from publisher's list"61"--stamped on cover"Unclassified. NYO-2131."Originally issued by the first author as an Sc. D. thesis, Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1959Contract AT(30-1)-207