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Caroline D. Nesaraja , Michael S. Smith

NUCLEAR DATA ACTIVITIES AT OAK RIDGE NATIONAL LABORATORY. Caroline D. Nesaraja , Michael S. Smith. NUCLEAR DATA ACTIVITIES. Nuclear Structure Data A-chain Evaluations. (M. Martin & C. Nesaraja). Nuclear Astrophysics Data

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Caroline D. Nesaraja , Michael S. Smith

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

  2. NUCLEAR DATA ACTIVITIES • Nuclear Structure Data • A-chain Evaluations (M. Martin & C. Nesaraja) • Nuclear Astrophysics Data • Evaluation and assessments of reactions & structure critical for stellar explosion studies • Closely coupling research and data activities 18F(d,n) (M. Smith, C. Nesaraja et al.) • 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. Smith & E. Lingerfelt)

  3. 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=58published in 2010 (Caroline Nesaraja, Scott Geraedts, Balraj Singh)

  4. 69Br Astrophysics Motivation: Sp(69Br) essential for studying the rp-process waiting point nucleus 68Se in X–ray burst Reaction path near the 68Se waiting-point. Waiting point nuclei: Nuclides along the rp process path that hinder or delay the abundance flow to heavier masses are called waiting point nuclei (64Ge, 68Se,72Kr …) Since 69Br is proton-unbound, proton capture is inhibited, and the process must wait for the long (t1/2=35.5 s) β decay of 68Se, essentially terminating the path to heavier masses. It is possible to bypass the waiting point by sequential 2p capture through 69Br This depends exponentially on the proton separation energy 69Br Reaction H. Schatz et al., 1998 • Work in progress: • include inENSDF • generate statistical model cross section for 68Se(p,g)69Br • convert to reaction rate with CINA • perform post processing element synthesis • X-Ray bursts calculations with new CINA rate Range of Sp where t1/2 eff is significantly below its beta decay t1/2 value

  5. Nuclear Astrophysics Data Motivation: Properties of 26Si levels important for the 25Al(p,g)26Si reaction rate which affect the production of galactic 26Al 26Si The 28Si(p,t)26Si*(p) Reaction and Implications for the Astrophysical 25Al(p,g)26Si Reaction Rate K.A. Chipps et al., Phys. Rev. C 82, 045803 (2010) First measurement of proton decay branching ratios for unbound 26Si levels

  6. Nuclear Astrophysics Data 131Sn ,133Sn Motivation: Provide nuclear structure information important for simulating r process nucleosynthesis in supernova explosions Assessmentsof selected nuclei related to ongoing research at ORNL NNDC-NUDAT 132Sn(d,p)133Sn • (d,p) transfer experiments made withradioactive130Snand 132Snbeams that are unique in the world • selectively populates single-neutron states in the recoiling nucleus 132Sn(d,p)133Sn results published in Nature (2010)

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

  8. Computational Infrastructure for Nuclear Astrophysics • 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 Frames from XRB simulation

  9. Nuclear Masses plot of the chosen reference dataset - AME2003 evaluated masses simple analyses of datasets are possible • nuclearmasses.orglaunched to aid research in nuclear masses • SHAREand 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

  10. CURRENT & FUTURE ACTIVITIES • Nuclear Structure/ Nuclear Astrophysics Data Evaluation and Assessments • Mass chain evaluation A=152 & A=69 • Reaction and structure assessments for 131Sn and 27Si • 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

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