Regular Article

Resonance parameter covariance representation: file32 versus file33

Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-EXP, SNC, 92260 Fontenay-aux-Roses France

^* e-mail: luiz.leal@irsn.fr

Received: 1 December 2017
Received in final form: 25 January 2018
Accepted: 28 May 2018
Published online: 5 September 2018

Abstract

Sensitivity and uncertainty analysis in error propagation studies are carried out based on nuclear data uncertainty information available in the basic nuclear data libraries such as ENDF, JEFF, JENDL and others. The uncertainty files (covariance matrices) are generally obtained from analysis of experimental data. In the resonance region, the computer code SAMMY is used for analyses of experimental data and generation of resonance parameters. In addition to resonance parameters evaluation, SAMMY also generates resonance parameter covariance matrices (RPCM). The intent of this paper is to discuss the use of the RPCM in contrast to the use of a cross section covariance matrix (CSCM) representation. For so, the resonance evaluation for ⁴⁸Ti in the resonance range from 10⁻⁵ eV to 400 keV is used. The RPCM is translated into two distinct CSCM by using a coarser and a finer group structures. The results are presented and discussions of the feasibility of using these covariance representations are depicted.