Photoelectric Atomic Absorption Cross Sections for Elements Z = 6 to 54 in the Medium Energy X-Ray Range (5 to 25 keV) — Part I

Abstract

Photoelectric atomic absorption cross sections have been calculated by means of hydrogen-like eigenfunctions for the atomic K, L, M and N sub-shells of the elements Z = 6 to 54, using revised screening constants and an extension of the theory. The absorption cross sections have been further separated into dipole and quadrupole components so that the numerical data can also be applied to the Borrmann effect.

Problems associated with the measurement of X-ray attenuation coefficients. I. Silicon. Report of the International Union of Crystallography X-ray Attenuation Project

“…Rather, the experimental values of Bearden & Burr (1967) were used. Among the other theoretical photoabsorption tables in the region of interest to crystallographers are those of Hildebrandt, Stephenson & Wagenfeld (1975) using hydrogen-like eigenfunctions and providing dipole and quadrupole cross-section components for Borrmann-effect applications. Band, Kharitonov & Trzhaskovskaya (1979) have also computed tables of photoabsorption cross sections, using relativistic self-consistent Dirac-Slater potentials and including parametrized photoelectron angular distribution information.…”

X-ray linear absorption coefficients for silicon and germanium in the energy range 5 to 50 keV

“…Proceeding from hydrogen-like eigenfunctions, Wagenfeld (1966), on the other hand, arrived at simple formulae, allowing fast calculations not only of normal but also of anomalous absorption cross sections important for the absorption of wave fields (Borrmann effect). Such calculations have been reported by Hildebrandt, Stephenson & Wagenfeld (1973, 1975a, Hildebrandt & Stephenson (1975), Stephenson (1976) and most recently by Gerward & Thuesen (1977) who also considered in detail contributions from thermal diffuse and Compton scattering.…”

Quadrupole Contribution to the Angular Resolved Photoemission from an X-Ray Interference Field

“…(6) R E h j j 2 a E 0 j j 2 . The total cross section is obtained from (6) and (7) by integrating over the whole spatial angle W of the escaping photoelectron.…”

“…(6): tn w 0X13 or w 7X5 o , i.e., dP 0X0208. It means, not taking quadrupole contributions into account, the determination of the (004) If the multipole term contribution is not known, then fitting an expression given by (6) …”