On the prediction and application of low energy Xray interactions
Abstract
For the low energy Xray region of 1002000 eV, the complete atomic interaction, coherent scattering and photoelectric absorption can be described by a complex scattering amplitude which may be given through the atomic scattering factor, f1 + if2. For this low photon energy region, it is shown by the relativistic quantum dispersion theory that the atomic scattering factors can be uniquely determined from simple relations involving only the atomic photoionization cross section dependence upon phonton energy. We have compiled state of the art tables for the photoionization cross sections for 94 elements and for the photon energy region of 3010,000 eV. With this compilation, we have established atomic scattering factor tables for the 1002000 eV region. By a summing of the complex, atomic scattering amplitudes, a low energy Xray interaction can be determined. Even for atoms in the molecular or solid state the scattering cross sectons remain atomiclike except for photon energies very near the thresholds. Using practical examples, the methods of calculation, with the atomic scattering factors, are reviewed here for the following: Xray energy deposition within materials (energy response of Xray photocathodes); transmission through a homogeneous medium: refraction; transmission through a random collection of uniform spheres: low angle scattering in an inhomogeneous medium; specular, Fresnel reflection (total and large angle reflection) at smooth boundary; and Bragg reflection from a periodic, layered system(reflection by crystals and multilayers).
 Publication:

Proceedings of the Low Energy Xray Phys. Program
 Pub Date:
 January 1982
 Bibcode:
 1982lexp.proc.....H
 Keywords:

 Coherent Scattering;
 Photoionization;
 X Ray Absorption;
 X Ray Scattering;
 Atoms;
 Electromagnetic Wave Transmission;
 Photocathodes;
 Photons;
 Reflection;
 Relativistic Effects;
 Scattering Cross Sections;
 Atomic and Molecular Physics