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Detailed Tabulation of Atomic Form Factors, Photoelectric Absorption and
Scattering Cross Section, and Mass Attenuation Coefficients in the Vicinity of
Absorption Edges in the Soft X-Ray (Z = 30-36,
Z = 60-89, E = 0.1 keV-10 keV), Addressing
Convergence Issues of Earlier Work
C. T. Chantler
School of Physics, University of Melbourne
Parksville, Victoria, 3052 Australia |
Abstract
Reliable knowledge of the complex x-ray form factor [Re(f) and
f″] and the
photoelectric attenuation coefficient (σPE) is required for crystallography, medical
diagnosis, radiation safety, and XAFS studies. Discrepancies between currently
used theoretical approaches of 200 % exist for numerous elements from
1 keV to 3 keV x-ray energies. The key discrepancies are due to the
smoothing of edge structure, the use of nonrelativistic wave functions, and the
lack of appropriate convergence of wave functions. This paper addresses these
key discrepancies and derives new theoretical results of substantially higher
accuracy in near-edge soft x-ray regions. The high-energy limitations of the
current approach are also illustrated. The energy range covered is 0.1 keV
to 10 keV. The associated figures and tabulation demonstrate the current
comparison with alternate theory and with available experimental data. In
general, experimental data are not sufficiently accurate to establish the
errors and inadequacies of theory at this level. However, the best experimental
data and the observed experimental structure as a function of energy are strong
indicators of the validity of the current approach. New developments in
experimental measurement hold great promise in making critical comparisons with
theory in the near future.
© 2001 American
Institute of Physics [S0047-2689(00)00604-8]. |
*
This online document reproduces the text and some of the figures from the
J. Phys. Chem. Ref. Data 29 (JPCRD 2000) publication. Hence, some
of the statements don't take into account the availability of data through the
online database. However, the online
database has been updated with values from (JPCRD 2000). For a complete
comparison of J. Phys. Chem. Ref. Data 24 (JPCRD 1995) with
(JPCRD 2000), please refer to the complete journal publication.
Online: May 2003
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