Nuclear Data in the ORNL Physics Division
The goal of nuclear data efforts in the Physics Division are to provide the best nuclear data for basic research and a wide range of applications including nuclear energy, national security, nuclear medicine, and space.
There are three main thrusts of our efforts, with the largest being the evaluation of the structure of groups of nuclei with the same mass - "mass chains”. We determine the “best” values of nuclear properties by combining previous values with the latest measurements, and publishing these in the Evaluated Nuclear Structure Data File (ENSDF) - the international standard for nuclear structure information. This is extremely detailed work, with some evaluations requiring 15000 lines of nuclear level information and taking up to a year to complete.
A second effort involves making critical assessments of the latest structure and reaction information to determine the best cross sections and thermonuclear rates for reactions that power exploding stars and create the elements of life. This work enables the determination of the astrophysical impact of measurements made at the Facility for Rare Isotope Beams (FRIB) and other nuclear accelerator facilities. Improved nuclear information is required for advanced studies of many unsolved puzzles in the cosmos, including the origin of the elements heavier than iron, the thermonuclear mechanisms in nova and supernova explosions, and the chemical evolution of the galaxy.
Our third effort is centered on developing online software systems that expand the utilization of standardized nuclear databases by the nuclear physics and astrophysics research communities. Our flagship system is the Computational Infrastructure for Nuclear Astrophysics, a unique online nuclear data “pipeline” that can process the latest accelerator measurements, incorporate them in custom astrophysical simulations, and visualize, analyze, and share the results with colleagues around the world. We also have systems specialized for the masses of subatomic nuclei and for the creation of elements in the early Universe. Our pioneering software approach has been spun off for use in materials science and theoretical astrophysics research.
Finally, there is a much broader range of activities in nuclear data across many disciplines at ORNL. We detail some of these efforts in our page on the Multidisciplinary Nuclear Data activities at ORNL.