Skip to Main content Skip to Navigation
Journal articles

Choice of positive distribution law for nuclear data

Abstract : Nuclear data evaluation files in the ENDF6 format provide mean values and associated uncertainties for physical quantities relevant in nuclear physics. Uncertainties are denoted as D in the format description, and are commonly understood as standard deviations. Uncertainties can be completed by covariance matrices. The evaluations do not provide any indication on the probability density function to be used when sampling. Three constraints must be observed: the mean value, the standard deviation and the positivity of the physical quantity. MENDEL code generally uses positively truncated Gaussian distribution laws for small relative standard deviations and a lognormal law for larger uncertainty levels (>50%). Indeed, the use of truncated Gaussian laws can modify the mean and standard deviation value. In this paper, we will make explicit the error in the mean value and the standard deviation when using different types of distribution laws. We also employ the principle of maximum entropy as a criterion to choose among the truncated Gaussian, the fitted Gaussian and the lognormal distribution. Remarkably, the difference in terms of entropy between the candidate distribution laws is a function of the relative standard deviation only. The obtained results provide therefore general guidance for the choice among these distributions.
Document type :
Journal articles
Complete list of metadatas

Cited literature [18 references]  Display  Hide  Download

https://hal-cea.archives-ouvertes.fr/cea-02304354
Contributor : Bruno Savelli <>
Submitted on : Thursday, October 3, 2019 - 11:00:55 AM
Last modification on : Tuesday, April 28, 2020 - 11:28:10 AM

File

LAh.pdf
Publisher files allowed on an open archive

Licence


Public Domain

Identifiers

Citation

Sébastien Lahaye. Choice of positive distribution law for nuclear data. EPJ N - Nuclear Sciences & Technologies, EDP Sciences, 2018, 4, pp.38. ⟨10.1051/epjn/2018047⟩. ⟨cea-02304354⟩

Share

Metrics

Record views

76

Files downloads

116