Nuclear data for astrophysics: resources, challenges, strategies, and software solutions

Abstract

Abstract. One of the most exciting utilizations of nuclear data is to help unlock the mysteries of the Cosmos -the creation of the chemical elements, the evolution and explosion of stars, and the origin and fate of the Universe. There are now many nuclear data sets, tools, and other resources online to help address these important questions. However, numerous serious challenges make it important to develop strategies now to ensure a sustainable future for this work. A number of strategies are advocated, including: enlisting additional manpower to evaluate the newest data; devising ways to streamline evaluation activities; and improving communication and coordination between existing efforts. Software projects are central to some of these strategies. Examples include: creating a virtual "pipeline" leading from the nuclear laboratory to astrophysics simulations; improving data visualization and management to get the most science out of the existing datasets; and creating a nuclear astrophysics data virtual (online) community. Recent examples will be detailed, including the development of two first-generation software pipelines, the Computational Infrastructure for Nuclear Astrophysics for stellar astrophysics and the bigbangonline suite of codes for cosmology, and the coupling of nuclear data to sensitivity studies with astrophysical simulation codes to guide future research. Background and motivationThe interdisciplinary field of nuclear astrophysics was established because fundamental knowledge of science at length scales of 10 −13 cm is required to address fascinating astrophysical questions such as the origins of the elements that make life possible, the evolution and explosions of stars, and the origin, composition, age, and ultimate fate of the Universe. Indeed, nuclear reaction information (e.g., cross sections, s-factors, reaction rates), nuclear structure information (e.g., masses, decays, resonance properties), and other specialized data sets (e.g., the nuclear equation of state) serve as the empirical foundation of our knowledge of many astrophysical sites and events. The availability of incredible images and data from powerful space-and ground-based observatories (e.g., Hubble, Chandra, Wilkinson, Keck, Subaru, and others), as well as the sophisticated astrophysical simulation codes that run on the fastest supercomputers, have led to a tremendous growth in this field. With new nuclear accelerator laboratories on the horizon (e.g., RIKEN RI Beam Factory, GSI/FAIR, RIA) that promise tremendous amounts of new data, this growth will definitely continue in the future.This growth is strong motivation to expand efforts to bolster the nuclear foundation of astrophysical studies. Improved nuclear science is needed, for example, to decipher the latest measurements using satellite observatories of longlived radionuclides [e.g., 26 Al, 44 Ti, 18 F] that are synthesized in and dispersed by supernova [1] and/or nova [2] explosions. Improved nuclear data -especially uncertainty and covariance information -is also ne...

Nuclear data resources and initiatives for nuclear astrophysics

“…The overall nuclear data needs for nuclear astrophysics studies are quite specialized [see, e.g., Smith (2003); Smith et al (2008); Smith MS. (2011)], spanning nuclear reaction data, nuclear structure data, and processed data (i.e., thermonuclear reaction rates); these data types are described briefly below. Because of the specific nature of these reaction and structure data needs (e.g., which isotopes, which reactions, which properties, which energies), specialized efforts are required to obtain the data through measurements and theory.…”