Nuclear Reaction Data Centres Research Articles

X4Pro – universal, fully relational EXFOR database

EXFOR library contains experimental reaction data compiled by the Nuclear Reaction Data Centers (NRDC) since 1970 and presenting data from more than 25,000 experiments in the EXFOR format with associated dictionaries and documentation. The IAEA-NDS provides nuclear data services primarily through computer systems built on relational databases and retrieval software. X4Pro is an extended EXFOR relational database designed for programmatic access to whole EXFOR content and distributed as local SQLite database with demo-codes in Python and Fortran.

Overview of the dissemination of n_TOF experimental data and resonance parameters

The n_TOF neutron time-of-flight facility at CERN is used for nuclear data measurements. The n_TOF Collaboration works closely with the Nuclear Reaction Data Centres (NRDC) network to disseminate the experimental data through the international EXFOR library. In addition, the Collaboration helps integrate the results in the evaluated library projects. The present contribution describes the dissemination status of n_TOF results, their impact on evaluated libraries and ongoing efforts to provide n_TOF resonance parameters in ENDF-6 format for further use by evaluation projects.

75 Years of Experimental Nuclear Reaction Data Compilations

The comprehensive experimental nuclear reaction data compilations were pioneered at the Metallurgical Laboratory, University of Chicago, and Los Alamos National Laboratory [1, 2] for the Manhattan Project needs. In 1947 many Manhattan Project alumni moved to a newly created Brookhaven National Laboratory (BNL) to work on nuclear physics research and data compilations [3–6] in support of nuclear science and reactor research activities. Since the beginning, the data project has relied heavily on computer technologies available at the time, and Brookhaven compilations have been stored in the Sigma Center Information Storage and Retrieval System (SCISRS) that predated the Exchange Format (EXFOR) database. In the following years, the reaction compilations evolved and gained an international component. Currently, the compilation efforts are coordinated by the Nuclear Reaction Data Centers network (NRDC) worldwide, which was founded in 1979 and operates under the auspices of the International Atomic Energy Agency (IAEA). The data compilations in the USA are coordinated by the National Nuclear Data Center (NNDC), Brookhaven National Laboratory for the United States Nuclear Data Program (USNDP). The database compilations represent one of the oldest continuously-operated scientific collaborations that continue to archive and disseminate nuclear data for nuclear science and technology.

The Experimental Nuclear Reaction Data(EXFOR)

The EXchange FORmat (EXFOR) experimental nuclear reaction database and the retrieval system provide access to the wealth of low- and intermediate-energy nuclear reaction physics data, and become the most comprehensive compilation of experimental nuclear reaction data. Currently, there are 13 participants (nuclear data centers) of the International Network of Nuclear Reaction Data Centers(NRDC) which has been organized under the auspices of the International Atomic Energy Agency(IAEA) to coordinate the collection, compilation, and dissemination of nuclear data on an international scale. As the participant of NRDC, China Nuclear Data Center(CNDC) does its best for measurement of nuclear reaction quantities induced by neutron and charged-particle and research on the technique of database construction. The formation, development and current situation of EXFOR library, and its format, compilation and retrieval system were introduced. The work on compilation of experimental nuclear reaction data and study of the database construction technique in China was briefly summarized, such as scanning Chinese journals, compiling EXFOR entries, developing software, providing nuclear data service in China, collaborating with NRDC and so on.

Progress in international collaboration on EXFOR library

The EXFOR library has served as the unique repository of experimental cross section and other nuclear reaction data for 50 years. The Nuclear Reaction Data Centres (NRDC) have compiled data sets from more than 22000 experimental works for the EXFOR library. Our collaboration and effort on improvement of EXFOR coverage are described in this paper, as well as tools for digitization of numerical data from graph images developed by us for EXFOR compilation.

Present Status of Neutron-, Photo-induced and Spontaneous Fission Yields Experimental Data

Nuclear reaction data collection, evaluation and dissemination have been pioneered at the Brookhaven National Laboratory since the early 50s. These activities gained popularity worldwide, and around 1970 the experimental nuclear reaction data interchange or exchange format (EXFOR) was established. The originalEXFORcompilation scope consisted only of neutron reactions and spontaneous fission data, while many other nuclear data sets were ignored. Due to the high cost of new experiments, it is very important to find and recover the previously disregarded data using scientific publications, data evaluations and nuclear databases comparisons.Fission yields play a very important role in applied and fundamental physics, and such data are essential in many applications. The comparative analysis of Nuclear Science References (NSR) and Experimental Nuclear Reaction (EXFOR) databases shows a large number of unaccounted experiments and provides a guide for the recovery of fission cross sections, yields and covariance data sets. The dedicated fission yields data compilation effort is currently underway in the Nuclear Reaction Data Centers (NRDC) network, and includes identification, compilation, storage and Web dissemination of the recovered data sets.

Completeness of experimental fission product yields in EXFOR database

The Nuclear Reaction Data Centres (NRDC) collaborate on worldwide compilation and dissemination of experimental nuclear reaction data by developing and maintaining the EXFOR database. With the growing interests in the fission product yields of various projectiles and a wide range of energies, several evaluation activities are ongoing. In line with these activities, the IAEA conducted completeness check of fission product yield data in EXFOR against two experimental datasets developed by the ENDF and UKFY library evaluators. The present status and statistics of these datasets as well as the result of the EXFOR completeness review are presented.

EXFOR – a global experimental nuclear reaction data repository: Status and new developments

Members of the International Network of Nuclear Reaction Data Centres (NRDC) have collaborated since the 1960s on the worldwide collection, compilation and dissemination of experimental nuclear reaction data. New publications are systematically complied, and all agreed data assembled and incorporated within the EXFOR database. Recent upgrades to achieve greater completeness of the contents are described, along with reviews and adjustments of the compilation rules for specific types of data.

Nuclear data activities at the n_TOF facility at CERN

Nuclear data in general, and neutron-induced reaction cross sections in particular, are important for a wide variety of research fields. They play a key role in the safety and criticality assessment of nuclear technology, not only for existing power reactors but also for radiation dosimetry, medical applications, the transmutation of nuclear waste, accelerator-driven systems, fuel cycle investigations and future reactor systems as in Generation IV. Applications of nuclear data are also related to research fields as the study of nuclear level densities and stellar nucleosynthesis. Simulations and calculations of nuclear technology applications largely rely on evaluated nuclear data libraries. The evaluations in these libraries are based both on experimental data and theoretical models. Experimental nuclear reaction data are compiled on a worldwide basis by the international network of Nuclear Reaction Data Centres (NRDC) in the EXFOR database. The EXFOR database forms an important link between nuclear data measurements and the evaluated data libraries. CERN's neutron time-of-flight facility n_TOF has produced a considerable amount of experimental data since it has become fully operational with the start of the scientific measurement programme in 2001. While for a long period a single measurement station (EAR1) located at 185 m from the neutron production target was available, the construction of a second beam line at 20 m (EAR2) in 2014 has substantially increased the measurement capabilities of the facility. An outline of the experimental nuclear data activities at CERN's neutron time-of-flight facility n_TOF will be presented.

Towards a More Complete and Accurate Experimental Nuclear Reaction Data Library (EXFOR): International Collaboration Between Nuclear Reaction Data Centres (NRDC)

The International Network of Nuclear Reaction Data Centres (NRDC) coordinated by the IAEA Nuclear Data Section (NDS) successfully collaborates in the maintenance and development of the EXFOR library. As the scope of published data expands (e.g. to higher energy, to heavier projectile) to meet the needs of research and applications, it has become a challenging task to maintain both the completeness and accuracy of the EXFOR library. Evolution of the library highlighting recent developments is described.

Developments of the EXFOR Database: Possible New Formats

The EXFOR database is a collection of experimental nuclear reaction data, maintained by the IAEA on behalf of the International Network of Nuclear Reaction Data Centres (NRDC). The format for the storage of such data was first described in 1969 and while there have been many incremental changes over the years so that the format is now capable of containing a very wide range of measurement results, there is a growing realisation that a major change is required. Consequently the IAEA Nuclear Data Section (NDS) organised a Consultant's Meeting on ‘Further Development of EXFOR’ in 2012. This was an opportunity for a range of international experts to discuss ways of improving EXFOR and while this focused on new formats there was also discussion on ways of storing new data, new output formats and software tools such as editors. This paper will discuss recent and proposed changes to enable new quantities to be stored (such as coincidence measurements and covariances), the range of output formats available (e.g. C4 and X4+) which make interaction with the data more user friendly and the possible use of XML to modernise the database.

Recent Developments in the Experimental Nuclear Reaction Data Library EXFOR

The International Network of Nuclear Reaction Data Centres (NRDC) provides nuclear reaction data services to users through collection and compilation of experimental nuclear reaction data in the EXFOR database. The database includes neutron-induced, charged-particle-induced, and photonuclear data for projectile energies up to 1 GeV. Sophisticated search options and user-friendly retrieval interface for downloading data in different formats have been developed at IAEA Nuclear Data Section. Additional output options such as data plotting capabilities are provided as well. The database is constantly revised and extended and at present contains about 20,000 experimental works accumulated in its 40 years of history. The paper will present several recent IAEA NDS activities related to the development of the EXFOR database and retrieval system.

The Role of the Nuclear Reaction Data Centres in Experimental Nuclear Data Knowledge Sharing

The International Network of Nuclear Reaction Data Centres (NRDC) consists of 14 data centers from 10 countries and 2 international organizations, and is collaborating for compilation, exchange and dissemination of various types of nuclear reaction data information. The nuclear data centers common data collection, the EXFOR library today contains experimental information and numerical data from more than 18,000 experiments consisting of more than 134,000 data sets mainly of nuclear reaction data for incident neutrons, charged-particles and photons with incident energy lower than 1 GeV. A brief history and the current status of NRDC collaboration are presented for EXFOR as well as CINDA and ENDF.

Nuclear Reaction Data Center Network: Past, Present, and Future

The Nuclear Reaction Data Centers provide online data services to users throughout the world. Services are tailored to the needs of users, and are continuously redesigned as the technology allows for more sophisticated use of the systems.