Evaluation of the chromium resonance parameters including resonance parameter covariance

The intent of this work is to report the results and describe the procedures utilized to evaluate the chromium isotopes' cross sections, i.e., ⁵⁰Cr, ⁵²Cr, ⁵³Cr, and ⁵⁴Cr, for criticality safety applications. The evaluations were done in the resolved resonance region using the reduced Reich-Moore R-matrix formalism. The novel aspect of this evaluation is the inclusion of new transmission and capture cross-section measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA) for energies below 100 keV and the extension of the ⁵³Cr energy region. The resonance analysis was performed with the multilevel R-matrix code, SAMMY, which utilizes the generalized least- squares technique based on the Bayes' theory. Complete sets of resonance parameters and resonance parameter covariance matrices (RPCMs) were obtained for each of the chromium isotopes from the SAMMY analysis of the experimental database.