MEASUREMENT OF THE ATOMIC SCATTERING FACTOR OF Ne, Ar, Kr, AND Xe

Journal Article · Tue Oct 15 04:00:00 EDT 1963 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.132.728· OSTI ID:4623457

Chipman, D R; Jennings, L D

To test the accuracy of the Hartree-Fock (HF) method and the reliability of x-ray measurements of the atomic scattering factor f, the scattering of Mo K alpha radiation by Ne, Ar, Kr, and Xe gases was determined. Values of f were obtained on an absolute basis with an accuracy of about 1/4%. Results at small angle yield the mean-square radius of the electron cloud (r/sup 2/)av and the dispersion correction. For Ne, Ar, and Kr, the values of (r/sup 2/) av are in good agreement with RF calculations. For Xe, the experimental value is significantly lower. Susceptibility results yield about 6% lower values in each case. The derived values of the dispersion correction are each more negative than those obtained from published absorption coefficients. At higher angles, the f values differ by less than 0.2 electron unit from the HF values for all the gases; even for Xe the approximate HF values presently available are more nearly accurate than the Thomas-Fermi-Dirac (TFD) values. It is concluded that a 4% discrepancy between theory and experiment found by Batterman, Chipman, and DeMarco for metal powders arose from solid-state effects or from difficulties in sample preparation. (auth)

• Research Organization: U.S. Army Materials Research Agency, Watertown, Mass.
• NSA Number: NSA-17-039772
• OSTI ID: 4623457
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 132; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANGULAR DISTRIBUTION
ARGON
ATOMIC MODELS
ATOMS
DIFFRACTION
ENERGY LEVELS
ERRORS
GASES
HARTREE-FOCK METHOD
KRYPTON
MEASURED VALUES
METALS
MOLYBDENUM
NEON
PHYSICS
POWDERS
QUANTUM MECHANICS
SCATTERING
SOLIDS
TESTING
THOMAS-FERMI MODEL
THOMAS-FERMI-DIRAC MODEL
X RADIATION
XENON