Capture Gamma-Ray Libraries for Nuclear Applications

Conference · Sat May 01 04:00:00 EDT 2010

OSTI ID:1023386

Sleaford, B W; Firestone, Richard B; Summers, N; Escher, J; Hurst, A; Krticka, M; Basunia, S; Molnar, G; Belgya, T; Revay, Z; Choi, H D

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF has been used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90percent of all the decay energy an is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We use CASINO, a version of DICEBOX that is modified for this purpose. This can be used to simulate the neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modelling of unknown assemblies.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Nuclear Science Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1023386
• Report Number(s): LBNL-4678E
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
22 GENERAL STUDIES OF NUCLEAR REACTORS
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
42 ENGINEERING
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
ACCURACY
CAPTURE
CROSS SECTIONS
DECAY
ENERGY LEVELS
EVALUATION
GAMMA CASCADES
HEAVY NUCLEI
IAEA
ND2010
Nuclear Data
ENDF
NEUTRON REACTIONS
NEUTRON SOURCES
NEUTRONS
NUCLEAR STRUCTURE
PROBES
PRODUCTION
SIMULATION
SPECTRA
THERMAL NEUTRONS
TRANSPORT