Back to Search
Start Over
Thermal scattering law of [formula omitted] : Integrating experimental data with DFT calculations.
- Source :
-
Annals of Nuclear Energy . Oct2018, Vol. 120, p778-787. 10p. - Publication Year :
- 2018
-
Abstract
- Improvements in determination of the thermal scattering law of moderator materials (measuring, calculating and validating) are important for accurate prediction of neutron thermalization in nuclear systems. In this work a methodology for producing thermal scattering libraries from the experimental data for polyethylene C 2 H 4 n is discussed. Double differential scattering cross section (DDSCS) experiments were performed at the Spallation Neutron Source of Oak Ridge National Laboratory (SNS ORNL). New scattering kernel evaluations, based on phonon spectrum for C 2 H 4 n , are created using the NJOY2016 code. Two different methods were used: direct and indirect geometry neutron scattering at ARCS and SEQUOIA, and VISION instruments, respectively, where the phonon spectrum was derived from the dynamical structure factor S(Q, ω ) obtained from the measured DDSCS. In order to compare and validate the newly created library, the experimental setup was simulated using MCNP6.1. Compared with the current ENDF/B-VII.1, the resulting RPI C 2 H 4 n libraries improved both double differential scattering and total scattering cross sections. A set of criticality benchmarks containing C 2 H 4 n from HEU-MET-THERM resulted in an overall improved calculation of K eff , although the libraries should be tested against benchmarks more sensitive to C 2 H 4 n . The DFT + oClimax method is used and is shown to be most comprehensive method for analysis of moderator materials. The importance of DFT + oClimax method lies in the fact that it can be validated against all data measured at VISION, ARCS and SEQUOIA, and experimental total scattering cross section measurements. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03064549
- Volume :
- 120
- Database :
- Academic Search Index
- Journal :
- Annals of Nuclear Energy
- Publication Type :
- Academic Journal
- Accession number :
- 130911768
- Full Text :
- https://doi.org/10.1016/j.anucene.2018.06.029