Moessbauer gamma-ray scattering in silicon and sodium

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6944911

Crow, Jr, M L

A Moessbauer gamma-ray diffraction instrument has been developed which uses high intensity sources. This work has used 40 Ci, 5.1d {sup 183}Ta sources produced by double neutron capture which yield 9 {times} 10{sup 10} photons/s for the 46.48-keV Moessbauer transition in {sup 183}W. A general analysis of the resolution function was carried out for gamma-ray scattering, which showed that its energy and momentum components can be factored independently with the energy resolution being determined by the Moessbauer resonance. Momentum resolution functions were measured in LiF and Si, and found to agree with the derivation. The high energy resolution provided by this technique allowed experimental separation of the elastic scattering from the inelastic thermal diffuse scattering (TDS). The momentum dependence of the TDS near the 444 reflection in silicon was measured, and shown to agree with a model using elastic constants and the resolution function. The Debye-Waller factor of sodium was measured as a function of temperature from 80K to 295K. The results were compared with the harmonic model using integrations over dispersion curves from the neutron scattering measurements of Woods et al. and the lattice dynamics calculations of Glyde and Taylor. The Debye-Waller exponent was shown to exceed the harmonic prediction by 23% at room temperature. This difference was attributed to anharmonic terms in the interatomic potential.

• Research Organization: Missouri Univ., Columbia, MO (USA)
• OSTI ID: 6944911
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
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400600 -- Radiation Chemistry
640300 -- Atomic
Molecular & Chemical Physics
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CONSTRUCTION
DATA
DATA ANALYSIS
DAYS LIVING RADIOISOTOPES
DIFFRACTOMETERS
ELEMENTS
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
GAMMA DIFFRACTOMETERS
GAMMA SPECTROMETERS
HEAVY NUCLEI
INFORMATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LOW TEMPERATURE
MEASURING INSTRUMENTS
MEASURING METHODS
METALS
MOESSBAUER SPECTROMETERS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
SEMIMETALS
SILICON
SODIUM
SPECTROMETERS
STABLE ISOTOPES
TANTALUM 183
TANTALUM ISOTOPES
TUNGSTEN 183
TUNGSTEN ISOTOPES