New thermal neutron scattering files for ENDF/B-VI release 2

Technical Report · Tue Mar 01 04:00:00 EST 1994

DOI:https://doi.org/10.2172/10192168· OSTI ID:10192168

MacFarlane, R E

At thermal neutron energies, the binding of the scattering nucleus in a solid, liquid, or gas affects the cross section and the distribution of secondary neutrons. These effects are described in the thermal sub-library of Version VI of the Evaluated Nuclear Data Files (ENDF/B-VI) using the File 7 format. In the original release of the ENDF/B-VI library, the data in File 7 were obtained by converting the thermal scattering evaluations of ENDF/B-III to the ENDF-6 format. These original evaluations were prepared at General Atomics (GA) in the late sixties, and they suffer from accuracy limitations imposed by the computers of the day. This report describes new evaluations for six of the thermal moderator materials and six new cold moderator materials. The calculations were made with the LEAPR module of NJOY, which uses methods based on the British code LEAP, together with the original GA physics models, to obtain new ENDF files that are accurate over a wider range of energy and momentum transfer than the existing files. The new materials are H in H{sub 2}O, Be metal, Be in BeO, C in graphite, H in ZrH, Zr in ZrH, liquid ortho-hydrogen, liquid para-hydrogen, liquid ortho-deuterium, liquid para-deuterium liquid methane, and solid methane.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10192168
• Report Number(s): LA--12639-MS; ENDF--356; ON: DE95002247
• Country of Publication: United States
• Language: English

Related Subjects

663430
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CROSS SECTIONS
ENERGY DEPENDENCE
MOMENTUM TRANSFER
NEUTRON REACTIONS
NUCLEAR DATA COLLECTIONS
NUCLEON-INDUCED REACTIONS AND SCATTERING
SCATTERING
THERMAL NEUTRONS