INTERNATIONAL NETWORK OF NUCLEAR STRUCTURE AND DECAY DATA EVALUATORS (NSDD)

25th Technical Meeting of the NSDD network - 50th Anniversary of the network

The 25th Technical Meeting of the NSDD network will be held from 15 to 19 April 2024, at the IAEA Headquarters, Vienna. Detailed information about the meeting, including presentations, are available at the meeting website.

This meeting marks a milestone in the history of the NSDD network, as it was exactly 50 years ago, at a Specialists' Meeting on Nuclear Data for Applications, IAEA, Vienna, 29 April - 3 May 1974 (INDC(NDS)-060), where expert groups on compilation and evaluation of nuclear structure and decay data from all over the world convened to "extend international cooperation in nuclear structure and decay data to meet the growing needs of the basic and applied sciences community for complete and up-to-date recommended nuclear structure and decay data."

The final recommendation of the meeting was:"to extend the existing compilation and evaluation efforts and co-operative links to an efficient and coherent network of international co-operation in order to improve the services to the users. This system should be based on the free international exchange of experimental as well as evaluated nuclear data."

To commemorate this milestone, the first session of the meeting will be devoted to a restrospective on the 50 years of the network with presentations from Jagdish Tuli (ENSDF Manager and Nuclear Data Sheets Editor, 1981 - 2016), Alan Nichols (IAEA Nuclear Data Section Head and NSDD Scientific Secretary, 2001 - 2009), Pavel Oblozinsky (Nuclear Data Section, 1993 - 2000; Head of the National Nuclear Data Center, 2000 - 2011), Paraskevi (Vivian) Dimitriou (NSDD Scientific Secretary, 2013 - present).

A tribute to one of the longest serving and most prolific evaluators, inspirational teacher and mentor, Balraj Singh (1941 - 2023), will be made in a special session on Wednesday, 17th April.

In Memoriam

Balraj Singh (1941 - 2023)

Our dear colleague, mentor, teacher, and friend, Balraj Sing, passed away on 9 October 2023.

Balraj completed his PhD at the University of Toronto in 1971 with Dr. Harry Taylor. The title of his thesis was "Directional Correlation and Multipole Mixing of Gamma Transitions in ¹³⁴Ba and ¹⁰²Ru". He then held post-doctoral fellowships at McMaster University (1971-1974), University of Toronto (1974-1976), and McGill University (1976-1978). He was a Research Scientist at Kuwait Institute for Scientific Research (KISR) from 1978 to 1984. In 1985 he moved back to Canada to start the Nuclear Data Program with Jon Cameron at McMaster University in Hamilton, Ontario. He remained at McMaster University until his retirement in 2013. From the mid 80s to early 90s he spent some time in Lawrence Berkeley National Laboratory where he worked with some of the nuclear data giants of the time, Virginia Shirley, C.M. Lederer, and Eddie Browne. After his retirement, he continued working for Brookhaven National Laboratory (US Nuclear Data program) until 2023.

In reality, Balraj never retired. For almost five decades he worked tirelessly on mass chain evaluations and other horizontal evaluation projects. As a nuclear data evaluator, Balraj was the single most prolific evaluator in the history of Nuclear Data Sheets and ENSDF, and one of the longest-serving members of the international network of Nuclear Structure and Decay Data evaluators (NSDD). A total of 80 published mass chains out of 300 in ENSDF have his name on them. That is 27% of all the mass chains; a feat only Balraj could accomplish.

In addition to data evaluation, in 1998 Balraj initiated the nuclear structure and decay compilation effort by establishing the eXperimental Unevaluated Nuclear Data List (XUNDL). He also inspired and supervised the development of several of the analysis and utility codes that are currently used in ENSDF evaluations. He published over 100 mass chain evaluations, more than any other ENSDF evaluator and contributed 6538 out of a total of 10584 datasets to the XUNDL database, that constitutes 62% of the database. Aside from the sheer volume, his work has always been appreciated for its high quality and comprehensiveness.

By actively engaging in meetings and passionately contributing to discussions on a wide range of topics, including nuclear physics, experimental techniques, evaluation procedures and policies, he played a pivotal role in advancing various aspects of nuclear structure and decay data evaluation.

He trained numerous students at McMaster University and supervised compilation and evaluation exercises at several of the IAEA-ICTP Workshops in Trieste, Italy. His idea to introduce mass chain evaluation as an exercise at the workshop has led to five publications of mass chains in Nuclear Data Sheets co-authored by the IAEA-ICTP workshop participants.

Balraj was a strong supporter of international cooperation and the NSDD network. He collaborated internationally and co-published mass chain evaluations with nuclear data evaluators from all around the world.

In addition to his exceptional expertise and immense dedication as an evaluator, Balraj was a warm, friendly, and compassionate person. He had a wonderful sense of humor, a genuine interest in his colleagues and the ability to put everyone at ease in his presence. He readily welcomed newcomers, inviting them to work with him and offering guidance and valuable advice.

Balraj leaves a legacy that encompasses the entire spectrum of data compilation and evaluation. Through his legacy his work will continue to impact the nuclear data and nuclear physics communities for many years to come.

Balraj wasn't just an outstanding scientist; he was a person of integrity and kindness, treating everyone with the utmost respect.

He will be sorely missed.

Logft review article

A new review article on the systematics of logft values has been published: Atomic Data and Nuclear Data Tables Volume 152, July 2023, 101584. It is an update of the 1998 publication by Singh et al., Nucl. Data Sheets, 84 (3) (1998), pp. 487-563.

24th Technical Meeting of the NSDD network: 24-28 October 2022, Canberra, Australia

The 24th meeting of the NSDD network is being hosted by the Australian National University in Canberra, Australia, from 24 to 28 October 2022. Representatives of the data centers and affiliated evaluators will gather to discuss the current status of mass chain evaluations, evaluation responsibilities, and analysis and checking code needs, as well as ENSDF formats and policies. Priority activities for the subsequent two years will also be agreed.

The meeting is hosted by the Australian National University (Tibor Kibedi, Andrew Stuchbery). It is an in-person meeting with a virtual component. More information is available on the meeting website.

Joint ICTP-IAEA Workshop on Nuclear Structure and Decay Data: experiment, theory and evaluation

The 10th in a row Joint ICTP-IAEA NSDD workshop is being held on 3-14 October 2022, at Miramare, Trieste. More information about the workshop programme and lecturers is available on the workshop website.

NSDD Spring meeting: ENSDF Evaluations, Policies and Procedures, Codes and Dissemination Tools

A preparatory meeting for the upcoming 24th Technical Meeting of the NSDD network was held on 4-7 April 2022. The purpose was to discuss policy proposals, evaluation issues, codes and dissemination tools in view of taking final decisions at the 24th Technical Meeting in October 2022.

The meeting (virtual) was attended by 50 participants, members of the network and collaborating evaluators, from 13 Member States. The meeting presentations are available from the meeting website. The summary report is published in INDC(NDS)-0850.

Updated Guidelines 2021

Updated guidelines for nuclear structure and dceay data evaluators are available ORNL/TM-2022/1835. The revision of the guidelines started in 2015 at the IAEA Specialized Workshop on Nuclear Structure and Decay Data Evaluations and was completed and edited by Murray Martin (ORNL) in April 2021.

New recommended electric quadrupole moments

Updated tables of recommended electirc quadrupole moments have been published by N.J. Stone in INDC(NDS)-0833. The data are available on the IAEA Nuclear Moments database.

Online Reporting meeting - May 2021

Recommended nuclear moments

Recommended nuclear dipole magnetic moments have been published by N.J. Stone in INDC(NDS)-0794 (long-lived states) and INDC(NDS)-0816 (short-lived states). The data are available on the IAEA Nuclear Moments database.

New AME2020 and NUBASE2020 release

The AME2020 and NUBASE2020 evaluations have been published in Chinese Phys. C 45 030002 (2021)(PDF), 030003 (PDF), and in Chinese Phys. C 41 030001 (2021) (PDF), respectively. The data files are available on the IAEA AMDC, and IMP, ANL webpages.

New r₀ parameters from alpha decay of even-even nuclei

New radius (r₀ ) parameters from alpha decay of even-even nuclei have been published by Sukhjeet Singh, Sushil Kumar, Balraj Singh, and A.K. Jain in Nuclear Data Sheets 167 (2020) 1-35 [doi.org/10.1016/j.nds.2020.07.001].

This work is an update of Yurdanur Akovali's 1998Ak04 work at Oak Ridge and includes updating half-lives, alpha-branching ratios, and r₀ values for all the even-even alpha emitters, including superheavy elements up to Og.
The new r₀ parameters will be incorporated in an upcoming updated version of the ALPHAD-radD code to extract alpha decay hindrance factors.

The Nuclear Structure Experimental Issues Database (NSEI)

The Nuclear Structure Experimental Issues (NSEI) Database was created with the purpose of collecting information on issues or gaps in experimental data that have been identified by the ENSDF evaluators or users of ENSDF and proposing them for further action.

The website was designed by IFIN-HH, Romania and the University of California, USA and is currently hosted on the UC Berkeley web servers. It can be accessed at: https://nucleardata.berkeley.edu/hpnsrl/

The website allows the users to add new experimental issues and also to upload comments to the existing issues. Both these actions are subject to the approval of the moderators of the website (i.e. the authors of the present report) who will then reach out to researchers who might potentially be able to address the issue.

Improvement of Analysis Codes for NSDD evaluations

Progress in the development of new analysis codes and editors for NSDD evaluations as well as improvements in existing codes and further needs was discussed at the Technical Meeting on Improvement of Analysis Codes for NSDD Evaluations, 3-7 December 2018, IAEA, Vienna.

More information as well as the meeting presentations are available on the meeting webpage. The meeting report has been published as INDC(NDS)-0774.

Evaluation of Nuclear Moments

A Consultant's Meeting was held at the IAEA, from 27 to 30 March 2017, to address the need for providing recommended nuclear magnetic dipole moments (DM), in addition to updating the evaluation of electric quadrupole moments (QM) performed by P. Pyykkö (Mol. Phys. 106 (2008) 1965) and N. Stone (INDC(NDS)-0650).

Meeting participants discussed the necessary corrections required for DMs to consider effects of diamagnetism, hyperfine anomaly, model assumptions for short-lived states, as well as advances in electric field gradient calculations for the QMs. They agreed to contribute to the production of a table of evaluated nuclear moments that would be made available in a published volume and incorporated in the online Nuclear Moments database.

More details on the discussions can be found in the meeting report INDC(NDS)-0732 while links to the presentations are available at the meeting website.

More news