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Breakout from the CNO Cycle

Breakout from the CNO Cycle. Joachim G ö rres University of Notre Dame And Joint Institute for Nuclear Astrophysics. “Sun and North Star” Brandenisha (5) & Ebony (4) From ART to SCIENCE: A JINA Outreach Project. http://www.nd.edu/~nsl. http://www.jinaweb.org.

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Breakout from the CNO Cycle

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  1. Breakout from the CNO Cycle Joachim Görres University of Notre Dame And Joint Institute for Nuclear Astrophysics “Sun and North Star” Brandenisha (5) & Ebony (4) From ART to SCIENCE: A JINA Outreach Project http://www.nd.edu/~nsl http://www.jinaweb.org

  2. Breakout FromThe Cold CNO Cycle Important For The Energy Production In Static Hydrogen Burning & 14N Production

  3. Breakout FromThe Hot CNO Cycle Important For The Energy Production In Explosive Hydrogen Burning, e.g. Nova, X-Ray Burst 15O(α,γ)19Ne 18Ne(α,p)21Na

  4. The End of the CNO Cycle: αp-process

  5. X-Ray X-Ray Burst: Superbursts 1 ½ hour decay time

  6. Indirect Method: 15O(α,γ)19Ne Reaction Rate Dominated By Resonance At 504 KeV Γα << Γγ~Γ ωγ ~ Γα 7 μeV  11.5 μeV (Mao et al. from Mirror 19F) Γα/Γ≈ 10-4 Need To Measure: Γ~1/τ ~ 10 fs

  7. 5.11 5/2+ 5.09 5/2+ 4.71 5/2- 4.68 5/2- 4.63 13/2+ 4.65 13/2+ 4.56 3/2- 4.60 5/2+ 4.55 5/2+ 4.55 3/2- 4.38 7/2+ 4.38 7/2+ 4.20 7/2- 4.01 4.03 9/2- 4.14 9/2- 4.00 7/2- 4.03 3/2+ 3.91 3/2+ 3.53 19Ne – 19F Mirror States ? 15N+alpha 19Ne 19F 15O+alpha ωγαγ Lifetime Information about: α-branching Sα

  8. Estimate (12 +9-5) meV 19Ne Coulomb Excitation Hackman et al., MSU Γ≈ Γγ Davidson & Roush 17O(3He,n γ) DSAM Rehm et al., ANL E2/M1 Ratio Γα/ Γ Davids et al., KVI < 6 10-4 <4.3 10-4

  9. 17O(3He,n-γ)19Ne Lifetime HPGe • Doppler Shifts And Geometry Uncertainties Are Cancelled. => Energy Measurement 45o 3He 3MeV 17O implanted n det HPGe 135o 3He 3MeV 28.5o • Maximize Doppler Shift Of Gamma Energies By Measuring Gammas Emitted Along The Same Direction As 19Ne Travels. => Lifetime Measurement 17O implanted 90o n det

  10. Result τ = (13 +9/-6) fs Or Γ ≈ Γγ = 51 meV Factor ≈4 Larger

  11. 5.11 5/2+ 5.09 5/2+ 4.71 5/2- 4.68 5/2- 4.63 13/2+ 4.65 13/2+ 4.56 3/2- 4.60 5/2+ 4.55 5/2+ 4.55 3/2- 4.38 7/2+ 4.38 7/2+ 4.20 7/2- 4.01 4.03 9/2- 4.14 9/2- 4.00 7/2- 4.03 3/2+ 3.91 3/2+ 3.53 19Ne – 19F Mirror States Within factor <2 ? 15N+alpha 19Ne 19F 15O+alpha ωγαγ Lifetime Information about: α-branching Sα

  12. Alpha Decay Branching 10% of 4 π

  13. 30º target orientation

  14. 5.35 6.01 4.38 4.60 5.42 4.55 4.03 5.09 4.14 4.20 4.71 Particle Identification Er 1 000 000 events dE … after three weeks:

  15. Reaction Kinematics right “before” left up down “after” 300 keV shift Kinematics !

  16. Time of Flight In progress Please, stay tuned in for the final results !!!!!

  17. Reaction Rate based on new information since 1986: 19Ne lifetime α-branching 15N(α,γ)19F α-spect. factor for 19F After 20 years …

  18. Wanpeng Tan Manoël Couder P.J. LeBlanc Shawn O’Brien Aaron Couture Joachim Görres Hye Young Lee Annalia Palumbo Ed Stech Elizabeth Strandberg Michael Wiescher “Dark City with Black Cat” Kenyon (5), Tokesha (5) & Lexis (5) From ART to SCIENCE: A JINA Outreach Project “The city is dark and sometimes black in the evening. Sometimes you can see the moon and stars and clouds and a cat.”

  19. Epilogue Sir Arthur Eddington http://www.nd.edu/~nsl http://www.jinaweb.org

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