Analytical approximations for x-ray cross sections III

Technical Report · Mon Aug 01 00:00:00 EDT 1988

DOI:https://doi.org/10.2172/7124946· OSTI ID:7124946

Biggs, F; Lighthill, R

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.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 7124946
• Report Number(s): SAND-87-0070; ON: DE88015366
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

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