NEUTRON THERMAL INELASTIC SCATTERING BY BOUND ATOMS. PROCEEDINGS OF THE NEUTRON THERMALIZATION CONFERENCE, APRIL 28-30, 1958, GATLINBURG, TENNESSEE

Technical Report · Sat Oct 31 04:00:00 EST 1959

OSTI ID:4216773

McReynolds, A W

In the energy range below about 1 ev, the cross section (k,k',T) for scattering of a neutron with propagation vector k, relative to the scatterer at temperature T, to k' is no longer characteristic of free atoms but dependent on interatomic binding forces. Using monoenergetic neutron beams, ranging from 0.05 to 11.3 ev, from crystal spectrometers at Brooknaven National Laboratory this dependence was studied by measurements of total cross section, the angular distritution, and the average scattered energy for H in various ehemical bonding states for C and Be. H in H/sub 2/O behaves qualitatively as if free, with smooth variation of both total cross section and energy loss. TMe tighter binding of H in ZrH/sub 1.5/ gives discrete energy states, 0.13 ev, characteristic of an isotropic harmonic oscillator. Energy loss per collision is negligible for neutrons of lower energy but has maxima at the 0.13, 0.26, etc., levels. There are corresponding peaks in total cross section above these energy thresholds in agreement with Fermi's theoretical curve. For carbon the predominaee of elastic diffraction seattering over inelastic necessitates higher resolution techniques. These show the product of cross section and energy loss per collision lower by about a faetor of 3 than the values for free carbon. (auth)

• Research Organization: General Atomic Div., General Dynamics Corp., San Diego, Calif.
• NSA Number: NSA-13-020341
• OSTI ID: 4216773
• Report Number(s): ORNL-2739(Paper III-B)
• Country of Publication: United States
• Language: English

Related Subjects

ANGULAR DISTRIBUTION
ATOMS
BERYLLIUM
BONDING
BOUND STATE
CARBON
CROSS SECTIONS
CRYSTALS
DIFFRACTION
ENERGY LEVELS
ENERGY RANGE
EV RANGE
HYDROGEN
INELASTIC SCATTERING
MEASURED VALUES
NEUTRON BEAMS
NEUTRON SPECTROMETERS
PHYSICS AND MATHEMATICS
RESOLUTION
SCATTERING
TEMPERATURE
THERMAL NEUTRONS
WATER
ZIRCONIUM HYDRIDES