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Title: Analytical approximations for x-ray cross sections III

Abstract

This report updates our previous work that provided analytical approximations to cross sections for both photoelectric absorption of photons by atoms and incoherent scattering of photons by atoms. This representation is convenient for use in programmable calculators and in computer programs to evaluate these cross sections numerically. The results apply to atoms of atomic numbers between 1 and 100 and for photon energiesgreater than or equal to10 eV. The photoelectric cross sections are again approximated by four-term polynomials in reciprocal powers of the photon energy. There are now more fitting intervals, however, than were used previously. The incoherent-scattering cross sections are based on the Klein-Nishina relation, but use simpler approximate equations for efficient computer evaluation. We describe the averaging scheme for applying these atomic results to any composite material. The fitting coefficients are included in tables, and the cross sections are shown graphically. 100 graphs, 1 tab.

Authors:
;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
OSTI Identifier:
7124946
Report Number(s):
SAND-87-0070
ON: DE88015366
DOE Contract Number:  
AC04-76DP00789
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; CROSS SECTIONS; COMPUTER CALCULATIONS; ABSORPTION; CALCULATION METHODS; ENERGY DEPENDENCE; ENERGY TRANSFER; EQUATIONS; SCATTERING; TABLES; X RADIATION; ELECTROMAGNETIC RADIATION; IONIZING RADIATIONS; RADIATIONS; 640302* - Atomic, Molecular & Chemical Physics- Atomic & Molecular Properties & Theory

Citation Formats

Biggs, F, and Lighthill, R. Analytical approximations for x-ray cross sections III. United States: N. p., 1988. Web. doi:10.2172/7124946.
Biggs, F, & Lighthill, R. Analytical approximations for x-ray cross sections III. United States. https://doi.org/10.2172/7124946
Biggs, F, and Lighthill, R. 1988. "Analytical approximations for x-ray cross sections III". United States. https://doi.org/10.2172/7124946. https://www.osti.gov/servlets/purl/7124946.
@article{osti_7124946,
title = {Analytical approximations for x-ray cross sections III},
author = {Biggs, F and Lighthill, R},
abstractNote = {This report updates our previous work that provided analytical approximations to cross sections for both photoelectric absorption of photons by atoms and incoherent scattering of photons by atoms. This representation is convenient for use in programmable calculators and in computer programs to evaluate these cross sections numerically. The results apply to atoms of atomic numbers between 1 and 100 and for photon energiesgreater than or equal to10 eV. The photoelectric cross sections are again approximated by four-term polynomials in reciprocal powers of the photon energy. There are now more fitting intervals, however, than were used previously. The incoherent-scattering cross sections are based on the Klein-Nishina relation, but use simpler approximate equations for efficient computer evaluation. We describe the averaging scheme for applying these atomic results to any composite material. The fitting coefficients are included in tables, and the cross sections are shown graphically. 100 graphs, 1 tab.},
doi = {10.2172/7124946},
url = {https://www.osti.gov/biblio/7124946}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Aug 01 00:00:00 EDT 1988},
month = {Mon Aug 01 00:00:00 EDT 1988}
}