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Computational Infrastructure for Nuclear Astrophysics

General Description

We created the first online "cloud computing" system for nuclear astrophysics, a virtual pipeline that enables results from the nuclear laboratory to be rapidly incorporated into astrophysical simulations. This system, the Computational Infrastructure for Nuclear Astrophysics or CINA, came online at nucastrodata.org in 2004 and now has Users in over 130 institutions in 30 countries. Users can upload, modify, share, compare, and visualize information of three different types -- nuclear cross sections, thermonuclear reaction rates, and nucleosynthesis simulations. There is also an online set of workflow tools to assist in evaluations of reaction rates, and more tools are being added at the request of Users. The system is available to anyone free of charge, and Users run applications and manage files on a remote server -- they only need an internet connection to access this system. The advantage of this approach is that Users never have to install software, worry about compability or security issues, or download patches. Registered Users get a disk allocation so that they can store their work and share their results (e.g., simulation results, thermonuclear reaction rate libraries) with others in a "virtual community" without resorting to email or ftp.

Detailed Description

Researchers can upload a table of cross section vs. energy into CINA, manipulate it (e.g., change the gain, renormalize), extend it (e.g., with a theoretical model), numerically integrate it into a thermonuclear reaction rate, parameterize the rate (fit with an analytical expression), manipulate the rate (e.g., rescale or change parameters), combine the rate into a library of rates, input the rate library into an element synthesis simulation, set up and execute the simulation, and visualize the results in customizable one- and two-dimensional plots and animations. Information at every step of the way can be stored online on our server. To enable researchers to quickly share data sets, we developed three "data spaces" in CINA: a "Public" space which hosts data that is published, archived, or for other reasons will remain unchanged; a "User" space which hosts a User's private data; and a "Shared" space which is open to all. This innovation enables Users to upload, modify, and utilize some of their own data sets in private -- including their own custom modifications of "Public" data sets -- and then move them into the "Shared" space to quickly enable collaborative work with colleagues without resorting to email, ftp, or other time-consuming file upload/download systems.

Technical Description

We have recently added a number of useful tools to CINA. For example, we now have analysis tools that enable Users to do more than just visualize their datasets. For example, Users can now search through their simulations to find waiting point nuclei and bottleneck reactions in nova and X-ray burst simulations based on a custom set of criteria. Such searches, which have never before been uniformly executed over a simulation, enable Users to locate nuclei and reactions that warrant further experimental or theoretical investigation. The figure at top right shows the results of one such analysis for an X-ray burst simulation. We have also added a tool to automate sensitivity analyses -- wherein the nuclear input is varied in a User-specified way and the system runs multiple simulation, collects the results, and conveniently generates plots of quantities such as abundances vs. input reaction rate. This quickly enables Users to determine if the change in an input reaction rate (from a new measurement or new theoretical prediction) will have an astrophysical impact. Our tool gives a 20-fold increase in productivity by automating the steps necessary for sensitivity studies. The figure at right shows the results of one such study -- the dependence of abundance yields on the 14O(alpha,p)17F reaction in a nova outburst.

Publications

• "Nuclear Data for Astrophysics Research: A New Online Paradigm", M.S. Smith, Proc. Int. Conf. Nuclear Data for Science and Technology 2010, J. Korean Physical Society 59 (2011) 761

• "Bottlenecks and Waiting Points in Nucleosynthesis in X-ray bursts and Novae", Michael S. Smith, Tomomi Sunayama, W. Raphael Hix, Eric J. Lingerfelt, and Caroline D. Nesaraja, Proc. Int. Symp. Origin Matter Evolution Galaxies 2010, AIP Conf. Proc. 1269 (2010) 439

• "Nuclear data for astrophysics: resources, challenges, strategies, and software solutions", M.S. Smith, Proc. Int. Conf. Nuclear Data for Science and Technology, EDP Sciences (2008), p. 1319

• "Waiting Points and Bottlenecks in Nova and X-ray burst Nucleosynthesis", Tomomi Sunayama, Michael S. Smith, Eric J. Lingerfelt, Kim Buckner, W. Raphael Hix, and Caroline D. Nesaraja, Proc. Int. Symp. Origin Matter Evolution Galaxies 2007, AIP Conf. Proc. 1016 (2008) 415

• "Thermonuclear Reaction Rate Libraries and Software Tools for Nuclear Astrophysics Research", Michael S. Smith, Richard Cyburt, Hendrik Schatz, Michael Wiescher, Karl Smith, Scot Warren, Ryan Ferguson, Eric J. Lingerfelt, Kim Buckner, and Caroline D. Nesaraja, Proc. Int. Symp. Origin Matter Evolution Galaxies 2007, AIP Conf. Proc. 1016 (2008) 466

• "New Features in the Computational Infrastructure for Nuclear Astrophysics", M. Smith, E. J. Lingerfelt, J. P. Scott, C. D. Nesaraja, K. Chae, H. Koura, L. F. Roberts, W. R. Hix, D. W. Bardayan, J. C. Blackmon, Proc. Int. Symp. Nuclear Astrophysics - Nuclei in the Cosmos IX, Geneva, Switzerland, June 25-30, 2006, Proceedings of Science, Pos(NiC-IX) 179 (2006)

• "Future of Nuclear Data for Nuclear Astrophysics Studies", M.S. Smith, Int. Conf. on Nuclear Data for Science and Technology (ND2004), Santa Fe, NM, Sept 26 - Oct 1, 2004, eds. R.C. Haight, M.B. Chadwick, T. Kawano, P. Talou, AIP Conf. Proc. 769 (2005) 1331

• "New Evaluations and Computational Infrastructure for Management and Visualization of Nuclear Astrophysics Data", C.D.Nesaraja, M.S. Smith, R.A. Meyer, D.W. Bardayan, J.C. Blackmon, K. Chae, M.W. Guidry, W.R. Hix, R.L. Kozub, E.J. Lingerfelt, Z. Ma, J.P. Scott, International Conference on Nuclear Data for Science and Technology (ND2004), Santa Fe, NM, Sept 26 - Oct 1, 2004, eds. R.C. Haight, M.B. Chadwick, T. Kawano, P. Talou, AIP Conf. Proc. 769 (2005) 1378


For More Information

The following links will let you learn more about this topic:

• Computational Infrastructure for Nuclear Astrophysics

Contacts

Michael Smith, smithms at ornl.gov