The simultaneous evaluation of the standards and other cross sections of importance for technology

Poenitz, W.P.; Aumeier, S.E.

doi:10.2172/658382

Cited by 23 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Extended energy ranges compared with the ENDF/B-VI results were obtained for the cross sections for H(n,n), 10 B(n,α), 10 B(n,α 1 γ), 235 U(n,f) and 238 U(n,f). A large database of measurements, a significant portion of which were assembled by Poenitz [212] for the ENDF/B-VI standards evaluation, was used for the present evaluation. In addition, the data sets introduced after the ENDF/B-VI evaluation and before the initiation of this evaluation were included in the database.…”

Section: A Overviewmentioning

confidence: 99%

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

Chadwick

Obložinský

Herman

et al. 2006

Nuclear Data Sheets

1,962

908

View full text Add to dashboard Cite

We describe the next generation general purpose Evaluated Nuclear Data File, ENDF/B-VII.0, of recommended nuclear data for advanced nuclear science and technology applications. The library, released by the U.S. Cross Section Evaluation Working Group (CSEWG) in December 2006, contains data primarily for reactions with incident neutrons, protons, and photons on almost 400 isotopes. The new evaluations are based on both experimental data and nuclear reaction theory predictions.The principal advances over the previous ENDF/B-VI library are the following: (1) New cross sections for U, Pu, Th, Np and Am actinide isotopes, with improved performance in integral validation criticality and neutron transmission benchmark tests; (2) More precise standard cross sections for neutron reactions on H, 6 Li, 10 B, Au and for 235,238 U fission, developed by a collaboration with the IAEA and the OECD/NEA Working Party on Evaluation Cooperation (WPEC); (3) Improved thermal neutron scattering; (4) An extensive set of neutron cross sections on fission products developed through a WPEC collaboration; (5) A large suite of photonuclear reactions; (6) Extension of many neutron-and proton-induced reactions up to an energy of 150 MeV; (7) Many new light nucleus neutron and proton reactions; (8) Post-fission beta-delayed photon decay spectra; (9) New radioactive decay data; and (10) New methods developed to provide uncertainties and covariances, together with covariance evaluations for some sample cases.The paper provides an overview of this library, consisting of 14 sublibraries in the same, ENDF-6 format, as the earlier ENDF/B-VI library. We describe each of the 14 sublibraries, focusing on neutron reactions. Extensive validation, using radiation transport codes to simulate measured critical assemblies, show major improvements: (a) The long-standing underprediction of low enriched U thermal assemblies is removed; (b) The 238 U, 208 Pb, and 9 Be reflector biases in fast systems are largely removed; (c) ENDF/B-VI.8 good agreement for simulations of highly enriched uranium assemblies is preserved; (d) The underprediction of fast criticality of 233,235 U and 239 Pu assemblies is removed; and (e) The intermediate spectrum critical assemblies are predicted more accurately.We anticipate that the new library will play an important role in nuclear technology applications, including transport simulations supporting national security, nonproliferation, advanced reactor and fuel cycle concepts, criticality safety, medicine, space applications, nuclear astrophysics, and nuclear physics facility design. The ENDF/B-VII.0 library is archived at the National Nuclear Data Center,

show abstract

Section: A Overviewmentioning

confidence: 99%

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

Chadwick

Obložinský

Herman

et al. 2006

Nuclear Data Sheets

1,962

908

View full text Add to dashboard Cite

show abstract

“…The R-matrix analyses for the light-element standards were done by Hale using the code EDA [3]. The simultaneous evaluation was done with the program GMA [4] written by Poenitz. A separate code written by Peelle was used to combine the simultaneous evaluation and R-matrix analyses and produce the final cross sections and uncertainties.…”

Section: Previous Cross Section Standards Evaluationsmentioning

confidence: 99%

“…Use of common samples and detectors for different measurements can lead to 100% correlations for these components of the uncertainties in the results of different measurements. These correlations were carefully analyzed by Poenitz [4] when data were entered (and updated) in the GMA database. Sets of experimental data obtained by the same group or at the same facility are usually combined in data blocks that account for the correlations between data sets.…”

Section: Underestimation Of Correlationsmentioning

confidence: 99%

Recent Work Leading Towards a New Evaluation of the Neutron Standards

Carlson

Pronyaev

Capote

et al. 2015

Nuclear Data Sheets

View full text Add to dashboard Cite

A new version of the ENDF/B library has been planned. The first step in producing this new library is evaluating the neutron standards. An evaluation is now underway with support from a Data Development Project of the IAEA. In addition to the neutron cross section standards, new evaluations are being done for prompt fission neutron spectra and a number of reference data. Efforts have been made to handle uncertainties in a proper way in these evaluations.

show abstract

“…The GMA database for the standards included 415 experimental data sets, pre-evaluated values, and thermal constants [14]. Some non-standard reactions were in the database because of their high accuracy and available ratios to the standards.…”

Section: Updating Of Gma Databasementioning

confidence: 99%

Status of the International Neutron Cross-Section Standards File

Pronyaev¹,

Badikov²,

Chen³

et al. 2005

AIP Conference Proceedings

View full text Add to dashboard Cite

A report is given of the progress achieved in an IAEA Co-ordinated Research Project (CRP) to improve the cross-section standards. The objectives of the CRP, started in 2002, were initially the understanding of the origin of the strong uncertainty reduction in R-matrix model fits and the improvement of the evaluation methodology. These aims were extended in 2003 to the preparation of new evaluations for the standard 6 Li(n,t), 10 B(n,α), 10 B(n,α 1 ), 197 Au(n,γ), 235 U(n,f), and 238 U(n,f) reactions. The methodology, codes, and experimental database developed by Poenitz and Hale for the ENDF/B-VI standards evaluation were taken as the basis for the new evaluation. The major results achieved by the CRP participants include the testing and intercomparison of a number of codes that can be used in the standards evaluation, updating the database of experimental results, analysis of the reasons leading to the strong uncertainty reduction in model fits, and a study of the bias in evaluated data caused by the Peelles's Pertinent Puzzle (PPP) effect, which has been widely discussed in the nuclear data community since the ENDF/B-VI standards evaluation was completed. Preliminary results of the new standards evaluation are shown. The use of the new 235 U(n,f) cross section leads to better consistency in calculations of some important integral experiments.

show abstract

The simultaneous evaluation of the standards and other cross sections of importance for technology

Cited by 23 publications

References 0 publications

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

Recent Work Leading Towards a New Evaluation of the Neutron Standards

Status of the International Neutron Cross-Section Standards File

Contact Info

Product

Resources

About