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Breakout from the CNO Cycle Joachim Görres University of Notre Dame And Joint Institute for Nuclear Astrophysics http://www.nd.edu/~nslhttp://www.jinaweb.org “Sun and North Star” Brandenisha (5) & Ebony (4) From ART to SCIENCE: A JINA Outreach Project
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Breakout FromThe Cold CNO Cycle Important For The Energy Production In Static Hydrogen Burning & 14 N Production
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Breakout FromThe Hot CNO Cycle Important For The Energy Production In Explosive Hydrogen Burning, e.g. Nova, X-Ray Burst 15 O(α,γ) 19 Ne 18 Ne(α,p) 21 Na
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The End of the CNO Cycle: α p-process
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X-Ray X-Ray Burst: Superbursts 1 ½ hour decay time
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Indirect Method: 15 O( α,γ ) 19 Ne Reaction Rate Dominated By Resonance At 504 KeV ωγ ~ Γ α Γ α << Γ γ ~Γ Need To Measure: Γ α /Γ ≈ Γ~1/τ 1 0 -4 ~ 10 fs 7 μeV 11.5 μeV (Mao et al. from Mirror 19 F)
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3.91 3/2 + 4.00 7/2 - 5.11 5/2 + 4.65 13/2 + 4.03 9/2 - 4.38 7/2 + 4.55 5/2 + 4.56 3/2 - 4.68 5/2 - 4.03 3/2 + 4.14 9/2 - 4.20 7/2 - 4.55 3/2 - 4.71 5/2 - 5.09 5/2 + 4.63 13/2 + 4.60 5/2 + 4.38 7/2 + 3.53 4.01 19 Ne – 19 F Mirror States 19 F 19 Ne 15 O+alpha 15 N+alpha Lifetime α - branching ωγ αγ SS ? Information about:
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Davids et al., KVI Rehm et al., ANL < 6 10 -4 <4.3 10 -4 Γ α / Γ 19 Ne Coulomb Excitation Hackman et al., MSU Davidson & Roush 17 O( 3 He,n γ ) DSAM Γ ≈ Γ γ Estimate (12 +9-5) meV E2/M1 Ratio
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17 O( 3 He,n- γ ) 19 Ne Maximize Doppler Shift Of Gamma Energies By Measuring Gammas Emitted Along The Same Direction As 19 Ne Travels. => Lifetime Measurement 3 He 3MeV 17 O implanted n det HPGe 3 He 3MeV 17 O implanted n det HPGe 28.5 o 45 o 135 o 90 o Doppler Shifts And Geometry Uncertainties Are Cancelled. => Energy Measurement Lifetime
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Result τ = (13 +9/-6) fs Or Γ ≈ Γγ = 51 meV Factor ≈ 4 Larger
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3.91 3/2 + 4.00 7/2 - 5.11 5/2 + 4.65 13/2 + 4.03 9/2 - 4.38 7/2 + 4.55 5/2 + 4.56 3/2 - 4.68 5/2 - 4.03 3/2 + 4.14 9/2 - 4.20 7/2 - 4.55 3/2 - 4.71 5/2 - 5.09 5/2 + 4.63 13/2 + 4.60 5/2 + 4.38 7/2 + 3.53 4.01 19 Ne – 19 F Mirror States 19 F 19 Ne 15 O+alpha 15 N+alpha Lifetime α - branching ωγ αγ SS ? Information about: Within factor <2
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Alpha Decay Branching 10% of 4 π
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30º target orientation
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Particle Identification dE ErEr 5.35 4.38 5.09 5.42 6.01 4.60 4.55 4.71 4.03 4.14 4.20 1 000 000 events … after three weeks:
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right left updown 300 keV shift Kinematics ! “before” “after” Reaction Kinematics
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Please, stay tuned in for the final results !!!!! Time of Flight In progress
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Reaction Rate based on new information since 1986: 19 Ne lifetime α -branching 1 5 N( α,γ ) 19 F α -spect. factor for 19 F After 20 years …
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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.”
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Epilogue Sir Arthur Eddington http://www.nd.edu/~nslhttp://www.jinaweb.org
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