1 / 20

Nuclear Astrophysics in EURISOL

Nuclear Astrophysics in EURISOL. Carmen Angulo UCL, Louvain-la-Neuve and CARINA network www.cyc.ucl.ac.be/CARINA. In charge of the Subtask “Astrophysics” for EURISOL since January 2006. Understanding the Universe.

babu
Télécharger la présentation

Nuclear Astrophysics in EURISOL

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nuclear Astrophysics in EURISOL Carmen Angulo UCL, Louvain-la-Neuve and CARINA network www.cyc.ucl.ac.be/CARINA In charge of the Subtask “Astrophysics” for EURISOL since January 2006 C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  2. Understanding the Universe The structure and the evolution of stars are determined by precise laws and properties involving many aspects of physics Hydrodynamic Thermodynamic Origin, Composition and Evolution of the Universe Astronomy Nuclear physics Atomic physics Cosmology C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  3. Hydrodynamic Thermodynamic Astronomy Origin, composition and evolution of the Universe Atomic physics Cosmology Masses b-decay rates n, e- and g interaction rates Nuclear Astrophysics Nuclear Physics Excited states properties Fission barriers Charged-particle and neutron induced reaction rates Synthesis of elements and energy production in stars (Stability vs. Collapse) C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  4. Explaining the Universe Long list of radioactive isotopes observed in the solar system Explanation of detected amount: test of stellar models and nucleosynthesis calculations Our current knowledge is very incomplete ! Figure from EURISOL report (based on Suess and Urey, Rev. Mod. Phys.,1956) C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  5. First CARINA workshop (June 2005) • For a coherent program in nuclear astrophysics one needs: • High-intensity, high-purity light- to medium-mass radioactive beams. • Equipped with a full range of experimental tools: • Series of gas targets(recirculation for rare gases) • A multi-stage recoil separator • A high-resolution magnetic forward spectrometer • Large-area, fine-granularity solid-state detectors or telescopes(on sharing basis; standard electronics and DAQ systems) • A dedicated high-resolution, high-efficiency gamma-ray detection system Find the final report at www.cyc.ucl.ac.be/CARINA Main conclusion C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  6. Nuclear astrophysics in EURISOL • Explosive scenarios: novae, X-ray burst, supernovae, neutron stars… The Hot CNO cycle and the rp process The r-process (the most challenging) • Moderate n-rich sites and AGB stars The s-process C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  7. 27Si 28Si 27Al 24Al 25Al 26Al rp-process onset 21Mg 22Mg 23Mg 24Mg 25Mg 26Mg 23Na 20Na 21Na 22Na NeNa cycle breakout from HCNO 18Ne 19Ne 20Ne 21Ne 22Ne 17F 18F 19F 14O 15O 16O 17O 18O HCNO 13N 14N 15N 13C 12C Hot CNO and rp-process 25Al(p,g)26Si 26Al(p,g)27Si 25Si(a,p)28P 30P(p,g)31S stable unstable 19Ne(p,g)20Na 18Ne(a,p)21Na 18F(p,a)15O 15O(a,g)19Ne 14O(a,p)17F End point of the rp-process: Sn-Sb-Te region (g,a), (p,g), b+ A < 106 Z N C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  8. Novae and X-ray bursters Observables • Capture and transfer reactions rates on ‘short lived’ nuclei (N to Te) • Nuclear masses and p-separation energies (near the proton drip-line) • b-decay half-lives (including decay from excited and isomeric states) Requirements Specific cases: Technical needs to be studied one-by-one C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  9. Targets • Inverse kinematics: proton- and alpha-rich targets • High intensity beams: need improved technologies • Extended-gas targets and gas cells • Jet-gas targets (specially suitable for recoil separators) • Cryogenic H and He targets Detectors • Particles: DSSSD … large solid angles … • Gamma: • Large gamma arrays • Recoil separators (preferred) No single solution for all cases ! C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  10. 18F(p,a)15O and nova gamma-ray emission • Gamma-ray emission from novae is dominated by positron annihilation following beta-decay of the newlysynthesized 18F • 18F (T1/2 = 110 min)  the annihilation radiation will be present after the expanding envelope of the novae becomes transparent. • Current and planned gamma-ray observatories  measurement of 18F abundances • Main destruction reaction: 18F(p,a)15O  Need cross section values at c.m. energies of 200-300 keV Snapshots of a Classical Nova Outburst (cortesy of J. José) C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  11. 18F(p,a)15O: a long standing problem ! More than 10 years of research: • Direct measurement: 18F(p,a)15O – done (LLN, Oak Ridge, Argonne) • Elastic scattering: 18F(p,p)18F – done (LLN, Oak Ridge) • Transfer, DWBA: 18F(d,p)19F – done (LNN, Oak Ridge) • Inelastic scattering: 19Ne(p,p’)19Ne – done, last week at LLN • Elastic scattering: 15O(a,a)15O – accepted at LLN, next year Beam (18F, 15O, 19Ne) intensities at LLN: 106 – 108 ions/s (0.1 – 10 pfA) C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  12. Need data at 200 – 300 keV: • a 18F beam of less than 4 MeV (less than 0.22 MeV/nucleon) • Cross section is orders of magnitude lower: • Beam intensities required of the order of 1012 ions/s (0.2 pmA) 18F(p,a)15O: present situation Rate at novae temperatures is still uncertain by orders of magnitude Data from D. Bardayan et al. (Oak Ridge) and N. de Séréville et al. (LLN). Curves: R-matrix model C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  13. s- and r-processes (p,g) and (a,g) reactions: inverse kinematics, low energy radioactive beams Experimental data for (n,g) reactions are practically missing • Indirect methods? • Accuracy?  astrophysics models • Direct measurements: • neutron beams (n_TOF, FRANZ…) • implanted targets > 1016 atoms/cm2 beams > 1010 ions/s (EURISOL?) C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  14. The case of 60Fe • Production of 60Fe (T1/2 ~ 106 yr) in massive stars (pre-supernovae) depends strongly on the very uncertain reactions: 59Fe(n,g)60Fe 60Fe(n,g)61Fe • Supernova output • Solar system formation triggered by a nearby supernova • The 60Fe isotope: • detected in deep sea sediments (Knie et al. 2004) • observed by INTEGRAL (Harris et al. 2005) – 60Co decay  60Fe beam : EURISOL? C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  15. Required beams Table from http://isolde.web.cern.ch/ISOLDE/ Required intensities: 1010 – 1012 ions/s (~ ppA – pmA) C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  16. The case of 107Pd • Spectroscopy observation of elements on the surface of very old metal-poor halo stars (early Universe) – Sneden et al. 2005 • Above barium (A > 138), agreement with solar r-process pattern: early robust r-process ? • Below barium, disagreement, underproduction compared to solar system: a second r-process ?  Ag abundance, specially low Mode 1: 107Ag(n,g)108Ag and 109Ag(n,g)110Ag are known Mode 2: 107Pd (b-) 107Ag, T1/2 = 6 106 yr But 107Pd(n,g)108Pd not known Implanted 107Pd target at EURISOL? C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  17. The r-process path Physics case • Nuclear structure properties of n-rich nuclei of paramount importance for understanding and modelling of the r-process Proposed experiments Does such a research program sound realistic to you? • Systematic study of nuclear structure of neutron-rich nuclei between N=50 and N=82: possible all elements from Fe to Sn, covering all “waiting points” ! Observables • Masses, half-lives, and possibly energies and spins of excited states, g.s. deformation, neutron capture rates… of about 150 nuclei Requirements • Low-energy intense beams • Penning trap mass spectrometer (masses) • Laser ion source (half-lives) C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  18. Requirements for NA Community at EURISOL EURISOL cater to a broad range of physics interests How much beam time can be devoted to nuclear astrophysics experiments (very time-consuming)? Yes, if dedicated LE accelerator and target-ion-source  see talk by Nigel Orr C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  19. Call for Ideas for FP7 • From a network to Joint Research Projects for NA  For details, please, check the CARINA website: www.cyc.ucl.ac.be/CARINA • Ideas to be discussed in the next CARINA workshop: Spring 2007 in Belgium (exact dates and venue to be announced soon) C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

  20. Thanks to: Maurizio Busso (Univ. Perugia) Alain Coc (CSNSM Orsay) Tom Davinson (Univ. Edinburgh) Jordi José (IEEC Barcelona) Gabriel Martinez-Pinedo (GSI Darmstadt) Alex Murphy (Univ. Edinburgh) Brian Fulton (Univ. York) Franz Käppeler (FZ Karlsruhe) Michael Heil (GSI Darmstadt) Alberto Mengoni (IAEA Vienna) Nigel Orr (LPC Caen) Endre Somorjai (ATOMKI Debrecen) Klaus Suemmerer (GSI Darmstadt) For some of the cases discussed here: references are in the EURISOL report C. Angulo, subtask “Astrophysics”, EURISOL Week, CERN, 27 – 30/11/2006

More Related