[en] The concept of the estimated data covariance files of ENDF/B is explored in detail. The relationship between uncertainties and ''possible mistakes'' is discussed in order to avoid likely misunderstanding concerning the use of the data covariance files. Some perceived strengths and weaknesses of the ENDF/B-V data covariance files are mentioned. 1 table

[en] The formats and procedures for the data covariances of ENDF/B-V are presented. 5 tables

[en] A complete statement of the uncertainties in data is given by its covariance matrix. It is shown how the covariance matrix of data can be generated using the information available to obtain their standard deviations. Determination of resonance energies by the time-of-flight method is used as an example. The procedure for combining data when the covariance matrix is non-diagonal is given. The method is illustrated by means of examples taken from the recent literature to obtain an estimate of the energy of the first resonance in carbon and for five resonances of ²³⁸U

[en] A PDP-10 FORTRAN IV computer program STAY'SL, which solves the dosimetry unfolding problem by the method of least squares, is described. The solution (the output spectrum and its covariance matrix) is calculated by minimizing chi-square based on the input data (the activation data, the input spectrum, the dosimetry cross sections and their uncertainties given by covariance matrices). The solution reflects therefore the uncertainties in all of the input data and their correlations. The correlations among the various dosimetry cross sections are taken into account; however, the activation data, input spectrum and cross sections as classes are assumed to be uncorrelated with each other

[en] The propagation of uncertainties in the input data is analyzed for the usual dosimetry unfolding solution. A new formulation of the dosimetry unfolding problem is proposed in which the most likely value of the spectrum is obtained. The relationship of this solution to the usual one is discussed

[en] The method of least squares is briefly reviewed, and the conditions under which it may be used are stated. From this analysis, a least-squares approach to the solution of the dosimetry neutron spectrum unfolding problem is introduced. The mathematical solution to this least-squares problem is derived from the general solution. The existence of this solution is analyzed in some detail. A chi²-test is derived for the consistency of the input data which does not require the solution to be obtained first. The fact that the problem is technically nonlinear, but should be treated in general as a linear one, is argued. Therefore, the solution should not be obtained by iteration. Two interpretations are made for the solution of the code STAY'SL, which solves this least-squares problem. The relationship of the solution to this least-squares problem to those obtained currently by other methods of solving the dosimetry neutron spectrum unfolding problem is extensively discussed. It is shown that the least-squares method does not require more input information than would be needed by current methods in order to estimate the uncertainties in their solutions. From this discussion it is concluded that the proposed least-squares method does provide the best complete solution, with uncertainties, to the problem as it is understood now. Finally, some implications of this method are mentioned regarding future work required in order to exploit its potential fully

[en] The code RFUNC is used at ORELA to analyze high resolution differential elastic scattering data from spin zero nuclides in the resonance energy region. This report presents the real R-Function formalism used in RFUNC and gives details of how the finite size corrections are currently made. Appendix A describes the input to the code RFUNC. Appendix B describes the input to a utility code MAKPA that transforms a resonance parameter file in SAMMY format into a resonance parameter file in RFUNC format. Appendix C describes the input to an adjunct code RFUNCXT that generates the contributions to the total cross section from resonances of different orbital and total angular momenta. The FORTRAN listing of the code RFUNC is given in Appendix D. 3 figs

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No abstract available

[en] The evaluation of neutron and gamma-ray-production cross sections for natural iron is considered. Improvements for ENDF/B-V MAT 1326 are described and graphically compared with the previous version. A summary of the previous version and a general description of the current status of the evaluation are also given. 25 figures