Caroline D. Nesaraja, Michael S. Smith NUCLEAR DATA ACTIVITIES AT OAK RIDGE NATIONAL LABORATORY

Nuclear Structure Data A-chain Evaluations Nuclear Astrophysics Data Evaluation and assessments of reactions & structure critical for stellar explosion studies Closely coupling research and data activities NUCLEAR DATA ACTIVITIES Online Software Systems Improve and expand functionality of the Computational Infrastructure for Nuclear Astrophysics nuclearmasses.org for the latest compiled, evaluated and theoretical masses Cloud Computing Initiative in Nuclear Data (M. Martin & C. Nesaraja) (M. Smith, C. Nesaraja et al.) (M. Smith & E. Lingerfelt) 18 F(d,n)

Nuclear Structure Data Responsibility: Actinide Evaluations A=241 – 249 or others requested from NNDC A=152 evaluation in progress (Murray Martin) A=69 evaluation in progress (Caroline Nesaraja) * also for astrophysics shown in next slide A=121 reviewed (Murray Martin & Caroline Nesaraja) A=125 reviewed (Murray Martin) A=58 published in 2010 (Caroline Nesaraja, Scott Geraedts, Balraj Singh)

Astrophysics Motivation: S p ( 69 Br) essential for studying the rp-process waiting point nucleus 68 Se in X–ray burst 69 Br Waiting point nuclei: Nuclides along the rp process path that hinder or delay the abundance flow to heavier masses are called waiting point nuclei ( 64 Ge, 68 Se, 72 Kr …) Work in progress: include in ENSDF generate statistical model cross section for 68 Se(p,) 69 Br convert to reaction rate with CINA perform post processing element synthesis X-Ray bursts calculations with new CINA rate Since 69 Br is proton-unbound, proton capture is inhibited, and the process must wait for the long (t 1/2 =35.5 s) β decay of 68 Se, essentially terminating the path to heavier masses. It is possible to bypass the waiting point by sequential 2p capture through 69 Br This depends exponentially on the proton separation energy 69 Br Reaction Reaction path near the 68 Se waiting-point. H. Schatz et al., 1998 Range of S p where t 1/2 eff is significantly below its beta decay t 1/2 value

Nuclear Astrophysics Data 26 Si Motivation: Properties of 26 Si levels important for the 25 Al(p,g) 26 Si reaction rate which affect the production of galactic 26 Al The 28 Si(p,t) 26 Si*(p) Reaction and Implications for the Astrophysical 25 Al(p,) 26 Si Reaction Rate K.A. Chipps et al., Phys. Rev. C 82, (2010) First measurement of proton decay branching ratios for unbound 26 Si levels

(d,p) transfer experiments made with radioactive 130 Sn and 132 Sn beams that are unique in the world selectively populates single-neutron states in the recoiling nucleus 131 Sn, 133 Sn Motivation: Provide nuclear structure information important for simulating r process nucleosynthesis in supernova explosions Assessments of selected nuclei related to ongoing research at ORNL NNDC-NUDAT Nuclear Astrophysics Data 132 Sn(d,p) 133 Sn 132 Sn(d,p) 133 Sn results published in Nature (2010)

Online Software Systems Rate Evaluation Work Flow Tools nuclearmasses.org bigbangonline.org rates sensitivity studies Computational Infrastructure for Nuclear Astrophysics at nucastrodata.org

CINA runs online at nucastrodata.org, free and open to all With a few mouse clicks, you can Rapidly incorporate nuclear results into stellar element burning simulations Run simulations and visualize results Perform sensitivity studies to show importance of nuclear data Share results and comments with online community Computational Infrastructure for Nuclear Astrophysics Frames from XRB simulation

nuclearmasses.org launched to aid research in nuclear masses SHARE and ACCESS work with scientific community (experimentalist, theorist, evaluators) Easily VISUALIZE & ANALYZE mass datasets Quickly COMPARE experimental or evaluated masses to 14 theoretical mass models Can help facilitate future NUCLEAR MASS EVALUATIONS by providing data visualization, manipulations & comparisons to theoretical mass models plot of the chosen reference dataset - AME2003 evaluated masses simple analyses of datasets are possible Nuclear Masses

CURRENT & FUTURE ACTIVITIES Nuclear Structure/ Nuclear Astrophysics Data Evaluation and Assessments Mass chain evaluation A=152 & A=69 Reaction and structure assessments for 131 Sn and 27 Si Future Mass Chain Evaluation within our region of responsibility Online Software Systems Computational Infrastructure for Nuclear Astrophysics - Implement a set of workflow tool for international collaboration in Nuclear Astrophysics - Explore how work flow tools can be utilized in the broader Nuclear Data Community Nuclear Masses - Explore role of nuclearmasses.org in future mass evaluation efforts