Development of the ENDF/B-VII.1 Evaluated Nuclear Data Library

In the run up to the final release of the ENDF/B-VII.1, we released several beta libraries to the CSEWG collaboration for testing. This allowed us to "kick the tires" of each release and flush out many bugs, before the library makes its way to our users. On this page, we collect summaries of all of the releases and note any major changes between them.

ENDF/B-VII.1 Final (Released Dec. 22, 2011)

The Cross Section Evaluation Working Group (CSEWG) released the ENDF/B-VII.1 library on December 22, 2011. The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0, including: many new evaluation in the neutron sublibrary (423 in all) and over 190 of these contain covariances, new fission product yields and a greatly expanded decay data sublibrary.

The major US laboratory contributors to the ENDF/B-VII.1 library are summarized below.

Sublibrary/Activity Major US Contributors
Neutron sublibrary LANL, BNL, ORNL, LLNL
Thermal scattering sublibrary LANL
Standards sublibrary NIST, LANL
Photonuclear sublibrary LANL
Decay data sublibrary BNL
Proton sublibrary LANL
d, t, 3He sublibraries LANL
Fission yield sublibraries LANL
Atomic data sublibraries LLNL
Data verification BNL
Data validation LANL, KAPL, Bettis, ANL, INL, BNL
Archival and dissemination BNL

You can find out more about ENDF/B-VII.1 by exploring the menu to the left.

Aside from numerous last minute bug fixes and fixes to the documentation, the entire 3He sublibrary was located and re-inserted into the project. The full list of differences between the neutron sublibrary in ENDF/B-VII.0 and this final release is available here.

Finally, we want to share a nice document summarizing the "provenance" of each evaluation in the neutron sublibrary, as compiled by Toshihiko Kawano (LANL). This is difficult work since evaluators often borrow from one another, after making minor changes, complicating the precise attribution of a part of the evaluation.

ENDF/B-VII.1 Beta 5 (Released Oct. 30, 2011)

The Beta5 "Happy Halloween" release included many fixes. The largest changes are: 19-F was reverted to ENDF/B-VII.0, and new evaluations were added for Tm-169,169,170 and Tl-203,205. Many tracker items were cleared as well as fixes were made to address issues uncoved during the covariance review. The ENDF-B-VII.1beta5.tgz tarball contains all of the ENDF sublibraries that will be included in the final ENDF/B-VII.1 release, however, only the neutron and decay sublibraries have been modified. See the wiki for the detailed list of changes. After this release, the library was frozen except for the most egregious errors and only changes to the documentation were supposed to be accepted. This release was tagged on Oct. 30, 2011.

ENDF/B-VII.1 Beta 4 (Released Sep. 9, 2011)

In this release, there were two main changes: a new decay sublibrary was added and, in response to serious validation problems uncovered in Beta3, BNL redid the Zr-90,91,92,93,94,95,96 evaluations. In addition, there were many small fixes, and we began task of clearing trackers and fixes pointed out by testing with FIZCON, CHECKR, PSYCHE and fudge. See the wiki for the detailed list of changes. This file was released on Sep. 9, 2011.

ENDF/B-VII.1 Beta 3 (Released May 24, 2011)

ENDF/B-VII.1beta3 should be close to the final VII.1. All files have been successfully processed by NJOY99.368 (modified to avoid problem in viewr) except 19-F and 35-Cl which need NJOY2010. Covariance reviews began with this release. After this release, an effort was made to limit the changes that would affect validation unless the fix was to improve an issue that arose during validation. This release was tagged on May 24, 2011.

ENDF/B-VII.1 Beta 2 (Released Feb. 22, 2011)

ENDF/B-VII.1beta2 is supposed to be very close to the final VII.1. New 78Kr, Ta, Re evaluations were added by LLNL, 23Na and 35Cl by ORNL and resonance fixes to Ni by BNL. All files were successfully processed by NJOY99.363 (modified) except 19-F and 35-Cl which need NJOY2010. This release was tagged on Feb. 22, 2011.

ENDF/B-VII.1 Beta 1 (Released Jan. 11, 2011)

ENDF/B-VII.1beta1 "Blizzard" is the next major beta release on the way to VII.1. All files have been successfully processed by NJOY99.336 except 19-F; it needs NJOY2010. There are still numerous errors reported by CHECKR and FIZCON. This file was released on Jan. 11, 2011.

ENDF/B-VII.1 Beta 0 (Released Oct. 22, 2010)

This was the initial release and contains only neutron sublibrary. It was been created using files submitted to BNL by 12:00 p.m. Oct. 22, 2010. Many changes were made in this library relative to ENDF/B-VII.0, the largest being the adoption of many minor actinides from the JENDL-4 data library. New evaluations for this release are 239U (LLNL), W (IAEA, ORNL), Xe (LLNL), Ni (ORNL), Ti (ORNL, LANL), K, Cl, 19F (ORNL), and 16O, 4He, 6Li, 9Be (LANL). 

Total number of files - 411.
New/Revised files - 125.