Caroline Nesaraja, Michael Smith, Daniel Bardayan, Jeffery Blackmon,

1. NUCLEAR DATA ACTIVITIES FOR ASTROPHYSICS AT OAK RIDGE NATIONAL LABORATORY Caroline Nesaraja, Michael Smith, Daniel Bardayan, Jeffery Blackmon, Eric Lingerfelt, Jason Scott, W. Raphael Hix Physics Division, Oak Ridge National Laboratory Kyungyuk Chae, Zhanwen Ma, Michael Guidry Department of Physics & Astronomy, University of Tennessee Chase Hard, Raymond Kozub, Jacob Sharp Department of Physics, Tennessee Technological University Jeffry Thomas Department of Physics & Astronomy, Rutgers University R. A. Meyer RAME, Inc.

2. Overview • Nuclear data for unstable nuclei – crucial for stellar explosion studies. • Holifield Radioactive Ion Beam Facility (HRIBF) at ORNL – provides opportunity to study reactions involving unstable nuclei. • Evaluations at ORNL – tightly coupled to measurements of nuclear reactions & structure information relevant to nuclear astrophysics • Computational Infrastructure for Management & Visualization of Nuclear Astrophysics Data – process nuclear data into formats used in nuclear astrophysics simulations

3. STARS LABORATORY Experiments at HRIBF, ORNL Analysis of experimental data – properties of excited states (spin, parity, total & partial decay widths, energy, spectroscopic factor); cross sections Data evaluations related to the measurements at HRIBF - analysis of all literature on the nuclei of interest - determine ‘best values” Processing and disseminating data for astrophysics simulations. www.nucastrodata.org

4. Motivation • Proton capture reactions on proton-rich unstable nuclei (rp process) • Structure & reaction information is needed to understand nova explosion and X-ray burst • Neutron capture reactions on neutron-rich • unstable nuclei (r process) • Information is needed to • simulate supernova explosions

5. Nuclear Data Activities Nuclear Structure Data • A= 241- 249 actinide region – Murray Martin Nuclear Astrophysics Data • Evaluation of Reactions critical for Stellar Explosions • Development of Computational Infrastructure for Nuclear Astrophysics Data

6. Nuclear Astrophysics Data Structure & Reaction Evaluations 14O(a,p)17F • Important transition reaction between the hot CNO cycle to the rp process • Multi-level R-matrix analysis is being performed on the 17F(p,a)14O, 17F(p,p)14Fgs, & 17F(p,p1)14F*495 differential cross sections • “Best Values” of properties for levels in 18Ne will then be used to determine new reaction rates J.C. Blackmon, 2001

7. High temperature rate better defined with 18F(p,p) measurement • upper limit set on 19Ne • resonant contributions, • new resonance found D.W.Bardayan, 2004 18F(p,a)17F & 18F(p, g)19Ne • important for understanding production of the observable radioisotope 18F in novae • & the heavy element production in X-ray burst . 18F(d,p)19F Kozub 2004 R.L Kozub, 2004 15N(a,a) analysis • 19Ne - 19F analog • assignments revised • based on R-matrix • analysis of old 15N(a,a) • data • changes rate at nova • temperatures • Low temperature rate better • defined with 18F(d,p) • measurement • new spectroscopic factors • assigned to low energy • resonances upper limit set w/o broad resonance re- evaluation in progress D.W.Bardayan, 2004

8. 82Ge(d,p)83Ge • First neutron transfer reaction measurement on a nucleus in the r-process path • Structure information important for studies of neutron capture rates • in the astrophysical r-process. J.S. Thomas , 2004 J.S. Thomas – Single –neutron excitations in neutron- rich N=51 isotones –SESAPS 2004

9. Available online at nucastrodata.org Computational Infrastructure Prior to the development of our Computational Infrastructure, there has been no easy, user friendly, uniform, reliable way to get most recent nuclear results into astrophysical models User friendly, platform independent software tools to process nuclear data into astrophysics models

10. Computational Infrastructure Components • Nuclear Data Evaluator’s Toolkit • Nuclear Data Manager • Nuclear Data Viewer Nuclear Data • Rate Generator • Rate Manager • Rate Library Manager Reaction Rates & Rate Libraries • Element Synthesis Simulator • Element Synthesis Manager • Element Synthesis Visualizer Element Synthesis Prior to the development of the Computational Infrastructure Suite, the entire process used to rely on numerous people and could take years, now it is done in minutes to an hour

11. Future Work • Evaluation work on • 29P(p, g)30S • 30P(p, g)31S • 33Cl(p, g)34Ar • 34Cl(p, g)35Ar • Murray Martin will be training me further to do evaluations • Expand functionality of the Computational Infrastructure • - adding new features • - modules may be useful in other areas of nuclear science

12. Summary • Information on unstable nuclei is important for stellar explosion studies • Radioactive beam facilities play a crucial role in obtaining this information • The information has to be evaluated, processed and distributed in order to be used in astrophysics simulation Nuclear Astrophysics Data Program at ORNL • Nuclear data evaluation activities at ORNL closely coupled to nuclear astrophysics measurements at HRIBF • New Computational Infrastructure with unique software tools hosted at nucastrodata.org – suite of codes for astrophysical related calculations, data management and data visualization