Select an element to go to a list of available correlation/covariance matrices for each isotope.
Project Lead: Eric F. Matthews
February 6, 2022
The matrices in this database before this date had been calculated with the ENDF/B-VII.1 and JEFF-3.1 evaluations. While ENDF/B-VII.1 and ENDF/B-VIII.0 are based on the same evaluation, there are slight differences between the two. The database has now been updated and the matrices are now reflective of the ENDF/B-VIII.0 and JEFF-3.3 evaluations.
A Monte-Carlo method for the generation of correlation and covariance matrices for independent and cumulative fission yields has been developed. The method uses a constrained Monte-Carlo resampling structure in order to vary evaluated fission yield libraries in a way that meets basic conservation principles. This results in the generation of correlation/covariance matrices with limited model bias and uncertainty; the matrices are primarily reflective of the evaluated fission yield uncertainties and correlations that arise from the evaluation process. This method has been applied to generate correlation and covariance matrices for all of the fissioning systems of the ENDF/B-VIII.0 and JEFF-3.3 evaluations, marking the first time such matrices have been generated for all of these systems. These covariance matrices have been published online for immediate public use. These correlation and covariance matrices can be used to improve uncertainty estimation in calculations of reactor antineutrino emission rates, decay heat problems, and nuclear forensics.
Publications and other works that use these matrices should cite the manuscript published on this code. Here is a BibTeX file that can be used. Below are some preformatted citations from various journals in the field:
© 2020-, Eric F. Matthews
This work was supported by the US Nuclear Data Program at LBNL under contract DE-AC02-05CH11231 (LBNL), the Department of Energy National Nuclear Security Administration through the Nuclear Science and Security Consortium under Award Number DE-NA0003180, and the NNSA Graduate Fellowship Program. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-MI-808481.