Covariance Workshop 2009
Covariance Workshop 2008
Click on the element, then on isotope (material) to get plots of uncertainties and correlation matrices. Numerical values can be retrieved using the link above the plots.
Covariance data are provided for radiative capture (or (n,ch.p.) for light nuclei), elastic scattering (or total for some actinides), inelastic scattering, (n,2n) reactions, fission and nubars over the energy range from 10-5 eV to 20 MeV. The library contains 387 files including almost all (383 out of 393) materials of the ENDF/B-VII.0. Absent are data for 7Li, 232Th, 233,235,238U and 239Pu as well as 223,224,225,226Ra, while natZn is replaced by 64,66,67,68,70Zn.
R.C. Little et al., "Low-Fidelity Covariance Project", Nuclear Data Sheets 109 (2008) 2828-2833; for those without full access to NDS we offer draft version of the paper.
Retrieval and plotting
The Sigma retrieval and plotting package developed by the NNDC is used to retrieve and plot uncertainties and correlation matrices. No processing is performed, Sigma directly plots MF33 data (cross section covariances) and MF31 data (nubar covariances). In some cases processing using cross sections (MF3) is required to get covariances and plots could not be produced.
Low-Fidelity Covariance Project, conducted by ANL-BNL-LANL-ORNL cpllaboration in FY2007-FY2008, was sponsored by the US Nuclear Criticality Safety program managed by DOE-NNSA.
Responsible: Pavel Oblozinsky, NNDC, Brookhaven National Laboratory