JEFF and EFF projects

The JEFF Nuclear Data Libraries
The latest version: JEFF-3.1.1
User feedback on JEFF
JEFF-β
JEFF meetings, next meeting: 1-3 December 2010 at the NEA, Issy-les-Moulineaux, France
JEFF and EFF project documentation
Radioactive Decay Data and Fission Yields
Status of new EFF evaluations
International databases on integral experiments (Nuclear science databases)
Implementation of the Resonant Scattering Kernel in Monte Carlo codes R. Dagan
Input decks for validation purposes (MCNP)

The JEFF Nuclear Data Library

The Joint Evaluated Fission and Fusion File (JEFF) project is a collaboration between NEA Data Bank member countries. The JEFF library combines the efforts of the JEFF and EFF/EAF Working Groups to produce a common sets of evaluated nuclear data, mainly for fission and fusion applications.

The latest version, JEFF-3.1.1, contains a number of different data types, including neutron and proton interaction data, radioactive decay data, fission yields, and thermal scattering law data. The data are available in ENDF-6 format (complete library) and in ACE format (neutron file only). Data are provided free of charge on CD/DVD and from the Web.

JEFF data can be easily displayed and compared with other evaluated or experimental data using the JANIS software.

JEFF meetings

The JEFF project is managed by a scientific co-ordination group (SCG) that meets twice a year. Technical achievements are reviewed at working group meetings in conjunction with the SCG meetings. The topics covered are:

Benchmarking, testing and evaluations
Radioactive decay and fission yield data
Experimental data
Fission product data
Fusion relevant data

The next JEFF/EFF meetings will be held at the NEA offices, Issy-les-Moulineaux, France, from Wednesday to Friday, 1-3 December 2010.

Documentation for the JEFF and EFF projects

Useful references

The documentation of the JEFF-3.1.1 library is available as JEFF Report 22 and JEFF Report 20, which are the accepted main reference for the JEFF-3.1.1 library.
The documentation of the JEFF-3.1 library is available as JEFF Report 21, which is the accepted main reference for the JEFF-3.1 library.
The documentation for the JEFF-3.0 library is available as JEFF Report 19, which is the accepted main reference for the JEFF-3.0 library.
The documentation for the JEF-2.2 library is available as JEFF Report 17, which is the accepted main reference for the JEF-2.2.

Other material has already been published describing the results of the thorough benchmark testing programme. Below, five references to the JEFF library project are listed. This list is complemented by the great deal of information provided in the JEF/DOC working papers (presented at the JEFF working group meetings).

A.J. Koning, et al. "The JEFF evaluated data project", Proceedings of the International Conference on Nuclear Data for Science and Technology, Nice, 2007
A.J. Koning, O. Bersillon, R.A. Forrest, R. Jacqmin, M.A. Kellett, A. Nouri, and P. Rullhusen, "Status of the JEFF Nuclear Data Library", Proceedings of the International Conference on Nuclear Data for Science and Technology, Santa Fe, 2004, p.177
R. Jacqmin, R. Forrest, J. Rowlands, A. Nouri, and M. Kellett, "Status of the JEFF Project", Jour of Nucl Sci and Techn, Supp 2, 2002, proceedings of the International Conference on Nuclear Data for Science and Technology, Tsukuba, 2001, p.54
C. Nordborg, M. Salvatores, "Status of the JEF Evaluated Data Library", Proceedings of the International Conference on Nuclear Data for Science and Technology, Gatlinburg, 1994, p.680
E. Fort, M. Salvatores, "JEF2 Validation", Proceedings of the International Conference on Nuclear Data for Science and Technology, Gatlinburg, 1994, p.768

JEF/DOC and EFF/DOC documents

Below are links to the lists of all the documents in the JEF/DOC and EFF-Doc series. Most of these documents are papers presented at the various working group meetings of the JEFF and EFF projects. These documents are available online in PDF format. (Note: The download of these documents is restricted to members of the JEFF and EFF Working Groups).

List of JEF documents

List of EFF documents

JEFF Reports

JEFF Reports are more detailed studies carried out on very specific aspects of the JEFF project and can be used for referencing purposes. These are available free of charge from the NEA.

List of JEFF Reports

Origin of the JEF-2.2 library evaluations

The origin of evaluations used in JEF-1 and their development through the JEF-2 libraries (up to JEF-2.2) are presented for quick reference in tabular form by isotope.

Origin of JEF-2.2 evaluations

For the origin of the evaluations in JEFF-3.1, please see the JEFF-3.1 library page.

User feedback on the JEFF library

The JEFF libraries have all undergone extensive benchmark testing. As a result of this testing, a considerable amount of valuable feedback has been provided. This feedback serves to identify deficiencies in the current version of the JEFF library, thus helping us to prepare improvements for the next release of the library.

Below is a list of the feedback received to date for the new as well as the older versions of the JEFF library. We would encourage users of the library to notify us of any additional problems which are not already included in this list.

Status of new EFF evaluations

The EFF project is producing new evaluations periodically and the status of these regarding date of release (actual or expected) along with the name of the responsible person/evaluator are given in the table. This allows benchmarking to be carried out on a given file with a known status and allows formal approval of an evaluation into the EFF file. There are currently no plans to release a completely new library within the EFF project name, but the EFF project and its new evaluations are part of the wider scope of the JEFF project. All EFF evaluations are held by the NEA and any questions regarding their availability or status should be addressed to

Status of new EFF evaluations

Last update: 30 July 2010