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Nuclear Astrophysics @ the Accelerator

Nuclear Astrophysics @ the Accelerator. O. Tengblad IEM-CSIC . EURO GENESIS workshop on reactions of Astrophysical Interest April 27-29 th IEM-CSIC Madrid. Astrophysics @ cmam. Life of stars. Formation of 12 C and 7 Be.

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Nuclear Astrophysics @ the Accelerator

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  1. Nuclear Astrophysics @ the Accelerator O. Tengblad IEM-CSIC EUROGENESISworkshoponreactionsofAstrophysicalInterest April 27-29th IEM-CSIC Madrid

  2. Astrophysics @ cmam Life of stars Formation of12C and 7Be Study of 10B(3He,p)12C* & 11B(3He,d)12C* Study of 4He(3He,g)7Be & 3He(4He,g)7Be Mariano Carmona Death of stars Production ofp-nuclei 197Au(a,n)200Tl reaction cross section R&D O. TENGBLAD EuroGENESISworkshop

  3. “Exact” A-body calculations possible for A12 Shell-model states Molecular-cluster states We can cover from drip-line to drip-line Break-up mechanism not fixed by kinematics Sequential? Direct? Crucial for bridging the A=5 and A=8 gaps in Big Bang and Stellar nuclear synthesis. Nuclear Structure & Astrophysics 12C & The triple alpha process 4He + 4He ↔ 8Be 8Be + 4He ↔ 12C + γ + 7.367 MeV a clustering

  4. - Single-nucleon excitations to 1p1/2,1d5/2 and 2s1/2: 1+, 2+1-, 2-, 3-, 4-1-, 2- Excited states: Theory 15.11 1+ 14.08 4+ 13.35 (2-) 12.71 1+ 11.83 2- 10.84 1- 2s1/2 ≈10 (0,2+) 1d5/2 9.64 3- 7.65 0+  7.27 1p1/2 1p3/2 4.44 2+ 12C* 1s1/2 g.s. 0+ n p 12C • Recenttheoreticalpapersdiscussingdifferent cluster modules, that can reproduce ratherwellthestates in 12C: • Bijker and Iachello, Ann. Phys. 298, 334 (2002). • KanadaEn’yo, Prog. Theo. Phys. 117 (2007) 65 O. TENGBLAD EuroGENESISworkshop

  5. Excited states: Recent experiments 2+ @ 9.9(3) MeV 12C(,’)12C* Nucl. Phys. A, 738, 268, 2004 2+ @ 9.0 MeV Included in the NACRE compilation (theory) Nucl. Phys. A, 656,3,1999 2+ @ 11.5 MeV 12C(,’)12C* Phys. Rev. C 68, 014305, 2003 (2+) @ 11.2 and 15.4 MeV TUNL compilation Nucl. Phys. A, 506, 1, 1990 15.11 1+ 13.35 (2-) 12.71 1+ 2+ @ 11.16 MeV 12C(12C,3) Phys. Rev. C 76, 034320, 2007. (also new 1-, 3-) 10.3 (0+) 2+ @ 9.6 MeV 12C(p,p’)12C* Nucl. Phys. A, 834, 621c, 2010 7.65 0+ 2+ @ 11.1 MeV 0+ @ 11.2 MeV b-decay 12N,12B Phys. Rev. C 81, 024303, 2010.  7.27 4.44 2+ g.s. 0+ O. TENGBLAD EuroGENESISworkshop 12C

  6. More questions: Decay mechanisms  12C  11.35 4+ 18.71   8Be 12C    3.03 2+ ≈10 0+ 14.08 4+ 16.11 2+ 11.83 2- 12.71 1+ 15.11 1+ 10.84 1- 9.64 3- 13.35 (2-) 7.65 0+ g.s. 0+ -0.092 7.27 12C 8Be 4He+4He Direct decay  • How do the different states decay ? • How is this related to the state structure ? Sequential decay O. TENGBLAD EuroGENESISworkshop

  7. 12C measured @ ISOLDE, JYFL & KVI Measured with high segmentation  decay mechanism / branching Experiment 2002-2004 Measured with implantation method  total energy Experiment april 2006

  8. How to produce the 12C* States @ CMAM  A+a C*  B*+b p 10B 13N*    11B d 9B* 3He @ 4.9 MeV + 12C* OR 3He @ 8.5 MeV + + 12C* O. TENGBLAD EuroGENESISworkshop

  9. The experiment: highly segmented Beam: 3He@ 4.9 and 8.5 MeVfrom 5 MV Tandetron  = 38%of 4 Targets: 18.9mg/cm210B enriched (90%) on 4 mg/cm2 C-backing 22.0 mg/cm211B with 4 mg/cm2 C-backing Reactions:10B(3He,p) 11B(3He,d) O. TENGBLAD EuroGENESIS workshop

  10. Particle Identification 3He +11B d+ 12C* a d p DE E

  11. MinimizeRandomCoincidences • Reduce the acceptance window by gate in TDC • 2.5 ms ADC window (data taking) • 0.1 ms TDC gate (analysis) • < 50 MeV/c • < 1 MeV • Energy & Momentum gates are independent 11B(3He,paaa)n TDC gate 11B(3He,daaa) data

  12. Esum=3/2*E1+0.092 MeV Esum() (MeV) E12C (MeV) Ei() (MeV) Selecting proton channel: p +  +  + a coincidences  Excitation Energy in 12C reconstructed SE 12C* 1 8Be(0+) 2 3 O. TENGBLAD EuroGENESISworkshop

  13. Partial branches a+a+a d+ 12C* 3He +11B O. TENGBLAD EuroGENESISworkshop

  14. Partial branches 9.64 3- 10.84 1- 11.83 2- 12.71 1+ 13.35 (2-) 7.65 0+ 3.03 2+ ≈10 0+ 11B(3He,daaa) data g.s. 0+ 7.27 MeV 12C 8Be O. TENGBLAD EuroGENESISworkshop

  15. Indirect Detection of g-decay p 10B 3He @ 4.5 MeV g • 17mg/cm2 • (+3 mg/cm2) 15.11 1+ 15.11 1+ 12C* g • The proton gives initial populated resonance in 12C 12.71 1+ • This state can emit gand populate a lower excited state 11.83 2- • The 3alphas give resonance populated in 12C after g-decay ≈10 0+ a a a 7.65 0+ 7.65 0+ 12C a+a+a 12C* O. TENGBLAD EuroGENESISworkshop

  16. Indirect Detection of g-decay Excitation energy: calculated from pvs invariant mass of 3a 3He+10B p+3 punch- throughs 3He+11B d+3 3He+11B n+p+3 O. TENGBLAD EuroGENESISworkshop M. Alcortaet al, NIM A605, 318 (2009).

  17. g-decay of 15.11 MeV 15.11 1+ 92.8% g width to bound states determined from p-12C coincidences 92.7 0.3 4.4 1.4 1.2 12.71 1+ 11.83 2- ≈10 0+ 7.65 0+ a+a+a 4.44 0+ 0.0 0+ 12C O. Kirsebomet al, PLB 680, 44 (2009)

  18. p-processStudies Production of most rare nuclei in the solar system p-nuclei Photon-disintegration reactions involved in the astrophysical p-process: (γ,n), (γ,p) & (γ,α) Nucleonsynthesis of the 35 stable p-rich nuclei, which cannot be reached in normal n-capture process Photon-disintegration: p-process (,n) + () Experiments to improve knowledge on α-nuclear potentials for astrophysical applications

  19. Production & study ofp-nuclei Optimum energy for CMAM Astrophysical energy region Gamow-peak 6-12 MeV Radiative α-capture reactions (α,p), (α,n) & (α ,γ) on proton-rich nuclei first experiments on 92Mo, 130Ba & 162Er Au-Mo-Au γ p α-beam Eα = 5-15 MeV Iα= 1µA n γ α Si-detector α-Intensity: 197Au(α,α)197Au 197Au(α,γ) reactions 197Au(a,n)200Tl D. Galaviz Redondo, Centro de Física Nuclear da Universidade de Lisboa

  20. 10 h after end of activation 197Au(a,n)200Tl 367 keV 200Tl 372 keV 40Ca(α,p)43Sc O. TENGBLAD EuroGENESIS workshop D. Galaviz D. Galaviz Redondo, Centro de Física Nuclear da Universidade de Lisboa

  21. 197Au(a,n)200Tl Literature value: 26.1 (1) h D. Galaviz D. Galaviz Redondo, Centro de Física Nuclear da Universidade de Lisboa

  22. R&D for experiments

  23. MonolithicDE-E telescope DE (N+) E detector (N-) 1 mm N+ Detector DE 500 mm N- Detector E Front cathode 0.5 µm Rearcathode 0.5 mm

  24. E FWHM 80 KeV DE 27Al Beams of 27Al & 23Na @ CMAM green  30 MeVblue  25 MeVred  20 MeVyellow  15 MeVdark blue  10 MeV 23Na

  25. Detectors: DSSSD  monolithic Si telescope DSSSD Monolito 5x5 cm2 16x16 strips á 3mm 256 pixel detectors á 3x3=9 mm2 32 electronicchannels Detector area: 5x5 cm2 64 pixel detectores á 3x3=9 mm2 128 electronicchannels Solidangle20% of the DSSSD and 4 times more electronicsneeded!!

  26. compact multiplexedreadout Area 64 x 3x3 mm2, DE 1mm, E 400 mm 128 ch electronics O. TENGBLAD FPA2009-07387

  27. compact multiplexedreadout

  28. 256 channelsmultiplexedto MDI-2 via a 20 pin twistedpair cable 2x MTM-64 128 channels Motorola power PC VME5055 Twisted pair 20 line MDI-2

  29. LaBr3 LaCl3 D E1 D E2 E 30 50 mm Phoswich forhigh E Gamma andProtondetection • Two crystals of different materials with a unique readout system?  Optically compatible

  30. Phoswich: 1st results  it works FWHM 4 % + ENERGY SPECTRUM WITH GATE B PHOSWICH TEMPORAL SPECTRUM O. TENGBLAD FPA2009-07387

  31. Phoswich detector response to 150 & 180 MeVprotons Phoswich response to 180 mevprotons FWHM < 1% LaBr3 PMT Flash ADC • Protonsloweddown in thetwocrystals • Protonescapingleavingpart of energy PMT • ProtonscatteredoutfromLaBr • Protonstopped in 1st crystal LaCl3 • Protonenteredfromthesideto 2nd crystal • Pile up & noise

  32. Reactionsstudy at CMAM Difficultto compare previousresults Uncertaintiesassociatedtothicknessandcompositionofthetarget } 170(p,γ)18F 170(p, α)14N Wewillperformourexpeiments in inversekinematics p(170,18F)γ p(170,14N)α LaBr3+LaCl3 Phoswich 9x { 15x15 mm2x (40+60)mm } crystals 3-1% resolution, 40% photopeak efficiency 0-20 MeV ISOLDE/JYFL Si-Ball: 36x4 quadrants of 1000 micron Si L.M. Fraile & J.Äystö, NIMA513 (2003) 28

  33. Collaborators • H.O.U. Fynbo, O. Kirsebom, S. Hyldegaard, K. Riisager • ÅrhusUniversity, Denmark • M. Alcorta, M.J.G. Borge, J-A Briz, M. Carmona, M. Cubero, • E. Nacher, A. Perea, O. Tengblad, • IEM-CSIC, Madrid, Spain • B. Jonson, T. Nilsson, G. Nyman • Chalmers Univ. of Technology, Göteborg,Sweden • B. R. Fulton, C. Aa Diget, N S Bondili • University of York, United Kingdom. O. TENGBLAD EuroGENESISworkshop

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