Open Access
ND 2007
Article Number 072
Number of page(s) 4
Section Evaluation of covariance matrices
Published online 17 June 2008
International Conference on Nuclear Data for Science and Technology 2007
DOI: 10.1051/ndata:07280

Neutron cross section covariances from thermal energy to 20 MeV

D. Rochman1, M. Herman1, P. Oblozinský1, S.F. Mughabghab1, M. Pigni1 and T. Kawano2

1  National Nuclear Data Center, Brookhaven National Laboratory, USA
2  T-16, Los Alamos National Laboratory, USA

Published online: 21 May 2008

We describe new method for energy-energy covariance calculation from the thermal energy up to 20 MeV. It is based on three powerful basic components: (i) Atlas of Neutron Resonances in the resonance region; (ii) the nuclear reaction model code EMPIRE in the unresolved resonance and fast neutron regions, and (iii) the Bayesian code KALMAN for correlations and error propagation. Examples for cross section uncertainties and correlations on 90Zr and 193Ir illustrate this approach in the resonance and fast neutron regions.

© CEA 2008