IAEA Nuclear Data Section meetings and workshops can be found here.

History of the NSDD Network

The International Network of Nuclear Structure and Decay Data (NSDD) evaluators is an international team of experts who provide recommended nuclear structure and decay data to be used in basic and applied research. These data include:

Evaluated nuclear quantities include the following: disintegration energies, radiation and transition probabilities, nuclear level schemes, excitation energies, half-lives, decay modes, spin-parity values, magnetic and electric multipole moments, and nuclear band structure.

The NSDD network was established in 1974 under the auspices of the International Atomic Energy Agency (IAEA), and includes 16 data centres and over 20 internationally-recognized experts from more than 10 countries. Network scientists evaluate nuclear structure and decay data for all isotopes on an agreed basis; they also compile the most recent experimental nuclear structure and decay published results. NSDD databases (ENSDF and XUNDL) contain these data in computerised format and are available both online and offline. The evaluations are also published in the journals Nuclear Physics A and Nuclear Data Sheets. The compilation and evaluation work makes extensive use of bibliographic information provided by the online NSR database which over the years has been developed and extended to provide servicies not only to the NSDD network but the nuclear science community at large.

The status of the NSDD network is described in detail in the document INDC(NDS)-0421.


Meetings of the International Network of Nuclear Structure and Decay Data Evaluators (NSDD) are coordinated by the NDS IAEA, while NNDC, Brookhaven National Laboratory, USA, is responsible for both the technical and database issues. NSDD members meet biennially (once every two years) to discuss the current status of the mass chain evaluations, evaluation responsibilities, and processing code needs, as well as ENSDF formats and policies. Priority activities for the subsequent two years are also agreed. These NSDD meetings are held alternatively at the data centres and IAEA Headquarters in Vienna.


The IAEA organizes jointly with the International Center for Theoretical Physics, Trieste, Italy, a workshop on "Nuclear Structure and Decay Data: Theory and Evaluation" in Miramare, Trieste, every second year. These workshops constitute a unique opportunity for scientists to be introduced to the formats and policies implemented in the evaluation of nuclear structure and decay data, as developed to produce the Evaluated Nuclear Structure Data File (ENSDF) and Nuclear Data Sheets for use in the nuclear physics and applications fields.