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18 Ne

GANIL Louvain la Neuve. 18 Ne. Secondary neutrons + fission BUT Also light RIB ’ s. Accelerator artist view. 40 MeV x 2 mA p / d RF SC linac. 2 nd – 6 th cryostats 40 SC HWR 176 MHz b 0 =0.15. 1 st cryostat 6 SC HWR 176 MHz b 0 =0.09.

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18 Ne

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  1. GANIL Louvain la Neuve 18Ne

  2. Secondary neutrons + fission BUT Also light RIB’s

  3. Accelerator artist view 40 MeV x 2 mA p / d RF SC linac 2nd – 6th cryostats 40 SC HWR 176 MHz b0=0.15 1st cryostat 6 SC HWR 176 MHz b0=0.09 176 MHz 3.8 m 1.5 MeV/u M/q2

  4. ECR Ion Source, LEBT and RFQ in situ The SARAF accelerator at Soreq, Israel. Winter 2007

  5. ….. 17F (a,p) 14O Fusion Reactions in the Sun:The CNO cycle Proposed at GANIL

  6. Mass accretion from a companion into a neutron star (black hole). • Role of 14O, 15O and 18Ne in the physics of x-ray bursts M. Wiescher et al. Erice Conference, 2007 J.L. Fisker et al., arXiv:astro-ph/070241 4He(15O,g)19NE

  7. The rp process and x-ray bursts - site of nucleo-synthesis X-Ray Bursts and the “rp” process These movies simulate an x-ray burst and the rapid-proton capture (“rp”) process. The calculation begins at T9=T/10^9 K=40 with only neutrons and protons. As time progresses and the temperature drops below T9=10, nucleons assemble into 4He nuclei then into heavier mass nuclides. Once T9 falls below about 4, the QSE among the heavy nuclei begins to break down. Charged-particle reactions freeze out, and flow to higher mass number occurs via nuclear beta decay. This is the classical r-process phase.

  8. Partial sample of representative papers The Astrophysical Journal, 650 (2006) 332 J.L. Fisker et al. TheImportanceof 15O(a,g) 19Ne to X-Ray Bursts and Superbursts Arxive-ph/0702412 Feb. 2007 J.L. Fisker et al. Experimental measurements of the 15O(a,g )19Ne reaction rate vs. observations of type I X-ray bursts Nuclear Physics A 718, (2003) 605 B. Davids et al. Alpha-decay branching ratios of near-threshold states in 19Ne and the astrophysical rate of 15O(α,γ)19Ne PRC 67 065809 (2003) K. E. Rehm et al. Branching ration Ga/Gg of the 4.033 MeV 3/2+ state in 19Ne Nuclear Physics A 688 (2001)465c. S. Cherubini et al. The 15O(a,g)19Ne reaction using a 18Ne radioactive beam

  9. A first experimental approach to the 15O + a elastic scattering - Eur. Phys. J. A27, 183 (2006) F. Vanderbist, P. Leleux, C. Angulo, E. Casarejos, M. Couder, M. Loiselet, G. Ryckewaert, P. Descouvemont, M. Aliotta, T. Davinson, Z. Liu, and P.J. Woods Recent experiments have determined Ga (or put limits to Ga) for levels in 19Ne up to 5.092 MeV excitation energy. A conclusion is that a direct measurement of the 15O(a, g)19Ne reaction in the region of astrophysical interest is currently impossible: 15O beams of intensity larger than 1011 pps on target would be required indeed to measure the 15O(a, g)19Ne cross-section in inverse kinematics in the energy region surrounding the first state above threshold, at 4.033 MeV….

  10. Long-learned lesson: “orders-of-magnitude improvement in sensitivity of measurement – enhanced understanding and possibilities”. 14N(d,2n)14O cross section and yield 14N(d,n)15O cross section and yield for a 2 mA deuteron beam for a 2 mA deuterons beam But, extraction of atomic oxygen…

  11. Tentative results Lower yield, but, better extraction..

  12. SPL SPS Decay Ring ISOL target & Ion source Cyclotrons Storage ring and fast cycling synchrotron PS The b beam (from Mats Lindroos – CERN) Production of an intense collimated neutrino (anti neutrino) beam directed at neutrino detectors via b decay of accelerated radioactive ions 6He 6Li e-n 18Ne 18Fe+n To the French Alps

  13. EURISOL INTERNATIONAL ADVISORY PANEL: “…. no progress has been made with the study of alternative production schemes of 6He and 18Ne using low energy beams and strongly recommends that this study be completed…. The outcome of this study is an essential ingredient for the analysis whether it is technically feasible to decouple EURISOL and the beta-beams completely

  14. Two stage production scheme Secondary target Primary target 9Be Target: C, Be, Li.. R=5 cm 9Be(n,2n)8Be 1 cm fast n 9Be(n,a)6He 40 MeV d 5 mA 200 kW 5 cm D=5 cm L=5 cm 7Li(d,xn)

  15. 6He production (n,a) cross section Production yield of the order of 10136He per 1 mA d@40 MeV Remember also11B(n,a)8Li

  16. 8Li energies of interest E(8Li [MeV]) 6 3

  17. R&D Steps Via neutron converter –6He, 8Li, .. Simulations – Geant4, MCNP – PRODUCTION rate of ~1013/mA!!! Converter design Target design – Extraction (Be fibers, “microballs..) Direct production –14,15O, 18Ne,.. Design of targets (heat) for direct production (O and Ne); materials (gas?), … Extraction. Nitrogen is “bad”. Perhaps C02? M. Loiselet, LLN 12C(3He,n)14O and 12C(4He,n)15O Experiment: Beam, Team, Detectors (RMS-like, Si ball, EXOGAM..)…

  18. Towards a full proposal – objectives and milestones. 2007-2009 Proposal to FP7 (Task 7.1) . Towards establishing a true collaboration. Initial target design. R&D studies of both n-converter and direct production. 2009-2011Target (s) manufacturing. Parameters for experimental setup. 2012-……. SPIRAL-II

  19. SUMMARY Presented ideas for light radio-nuclei production and use at SPIRAL2 Scientific Case Calculations and simulations exist – but much more R&D needed “Road Map” towards a full experiment OPEN COLLABORATION – participation welcome!!

  20. Type II Supernovae 8Li(a,n)11B ‘2000 g.s.

  21. Secondary target Li Primary target 9Be R=5 cm 9Be(n,2n)8Be fast n 1 cm 9Be(n,a)6He 2 mA 80 kW 5 cm D=5 cm L=5 cm 7Li(d,xn) MCNP 6He yield simulation Simulated by Keren Lavie Assuming: • a source target of solid Beryllium in place of liquid Li. • Secondary Be target at natural density.

  22. Typical X-ray bursts: • 1036-1038 erg/s • duration 10 s – 100s • recurrence: hours-days • regular or irregular Frequent and very brightphenomenon ! (stars 1033-1035 erg/s)

  23. Production of 14O

  24. msm = 3•10-19 [mn/eV], but…..

  25. neutron flux in secondary target 100% natural density MCNP K. Lavie

  26. flux cross section overlap

  27. production efficiency as function of Be target slide MCNP K. Lavie

  28. Production of other isotope Analytical calculation

  29. Production of other isotope

  30. A new idea …. There is a very noticeable lack of accelerators for STABLE BEAMS at HIGH CURRENT. There is now even a separate European network for such present and future facility. Say, one installs at the SARAF a high-q ECR source and then one can obtain beams of 240 MeV 12C, 320 MeV 16O etc. at hundreds of mA Build a high-efficiency- large solid angle Recoil Mass Separator or a gas-filled magnet for nuclear structure and astrophysics. To be explored…(!?)

  31. Primary target fast n spectrum <En>=15 MeV IFMIF S.P.Simakov et al. 2002

  32. Accelerator layout 40 MeV x 2 mA p / d RF SC linac 176 MHz 3.8 m 1.5 MeV/u M/q2 1st cryostat 6 SC HWR 176 MHz b0=0.09 2nd – 6th cryostats 40 SC HWR 176 MHz b0=0.15

  33. Table 1 – comparison of 6He production yield for different laboratories • Assume the transmission efficiency for 6He extraction ionization and transport is ~ 1% [25].

  34. Model dependence of the neutrino-deuteron disintegration cross sections at low energies http://il.arxiv.org/abs/nucl-th/0702073v1

  35. EURISOL INTERNATIONAL ADVISORY PANEL- Recent Report: “… no progress has been made with the study of alternative production schemes of 6He and 18Ne using low energy beams and strongly recommends that this study be completed within the next year. The outcome of this study is an essential ingredient for the analysis whether it is technically feasible to decouple EURISOL and the beta-beams completely.”

  36. Next step in simulation Optimization: • By adding a Be reflector √ • As function of Be target density, structure • Including construction metals • As function of L, D and R R L D

  37. Target NO Post-acceleration results Interest Post-acceleration results And Now What??..... 6He and the magnetic moment of the neutrino Interest 8Li(a,n)11B and Type II Supernovae Target 14O(a,p)17F and 15O(a,g)19Ne and x-ray bursts - nucleo-synthesis Target Post-acceleration results Interest

  38. Present Status – SARAF Phase I – March ‘07 • Building ready • Source and LEBT ready • RFQ installed and being conditioned • SC resonators installed in cryostat, individually tested, waiting for final test of entire module. • First beam at ~4-5 MeV – Summer ’07

  39. Yield Calculations: Sergei Vaintraub, HUJI 80 6He, 8Li and others also via a d+ 7Be neutron converter; the 11B(n,a)8Li and 9Be(n,a)6He reactions

  40. Examples of Reactions with RNB’s for Astrophysics • 8B(p,g)9C • 8B(a,p)11C • 9C(a,p)12N • 11C(p,g)12N

  41. 11C(p,)12N, S(E) = E  (E) exp(2) Direct Capture is important at stellar energies except for the places of resonances , 2+, Ex=0.960 MeV and 2- 1.191 E0=0.030, E0=0.020 MeV for CNO E0=0.18, E0=0.16 MeV for Novae

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