Prior for Structural Materials

Abstract

The construction of a library containing prior cross sections and related covariance matrices for nine frequently measured reaction channels of 276 structural materials from 1 to 150 MeV is presented. This library provides a starting point for future evaluations and reduces them to the analysis of experimental data. The prior cross sections were calculated using the nuclear reaction programs of TALYS1.0 and TALYS1.2 with the implemented global and local neutron and proton optical potential parameter sets. The prior covariance matrices contain contributions stemming from parameter uncertainties and model deficiencies. The associated procedures are discussed and an example evaluation with these prior cross sections and covariance matrices is shown for one specific isotope. These developments are of great importance with regard to the reliability of evaluations strongly based on model calculations. This is particularly true for the extension of the energy range as requested by the development of novel nuclear technologies.