Yttrium ENDF/B-VII Data from Theory and LANSCE/GEANIE Measurements and Covariances Estimated using Bayesian and Monte-Carlo Methods

Uncertainties of mass extrapolations in Hartree-Fock-Bogoliubov mass models

“…To test the sensitivity of our results with respect to the adopted weighting function, we also consider in the present work the two values of 0.6 and 1 MeV, as well as the original weighting function [Eq. (3)] introduced in the BFMC method [32][33][34]. Future analysis along the UMC-B approach will be reported in a forthcoming work.…”

“…It is possible to estimate the impact of such model-parameter uncertainties on calculated masses by propagating the parameter uncertainties by Monte Carlo sampling constrained by available experimental masses [29]. The method considered here is similar to the backward-forward Monte Carlo (BFMC) method [32][33][34]. It relies on the sampling of model parameters and on the use of a generalized χ 2 estimator to quantify the likelihood of each model calculation result respective to a given set of experimental constraints on calculated masses.…”

Evaluated Iridium, Yttrium, and Thulium Cross Sections and Integral Validation Against Critical Assembly and Bethe Sphere Measurements

“…Our results for the new 89 Y(n, 2n) cross sections to the ground state and m1, m2 isomers are documented in detail in Refs. [5,6].…”

“…Unmeasured contributions (e.g. neutron sidefeeding reactions that populate the state without accompanying gamma-ray emission) were taken from GNASH code predictions [5,6]. Prior to using the GNASH code for the unmeasured contributions, the predictive capability of GNASH was assessed through comparisons between measured and predicted gamma-ray transitions, and assessed to be accurate to about 20% [5,6].…”

“…One of the most important quantities for neutron dosimetry using yttrium is the ratio of 87 Y/ 88 Y atoms after an irradiation, and the dominant contribution to the production of 88 Y is the (n, 2n) cross section on 89 Y. Updates to this 89 Y(n,2n) cross section were found to be necessary owing to new data from LANSCE/GEANIE on the production of the 88 Y ground state and isomers, and were performed by Chadwick et al in 2003 [5] and are discussed further in this paper and in a companion paper [6] in this issue of Nuclear Data Sheets.…”