1 / 14

Alain Coc CSNSM ( C entre de S ciences N ucléaires et de S ciences de la M atière, Orsay )

Nuclear Astrophysics in France. Alain Coc CSNSM ( C entre de S ciences N ucléaires et de S ciences de la M atière, Orsay ) + material from : F. Hammache , N. de Séréville , F. de Oliveira, V. Tatischeff , J. Margueron.

orde
Download Presentation

Alain Coc CSNSM ( C entre de S ciences N ucléaires et de S ciences de la M atière, Orsay )

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 France • Alain Coc • CSNSM • (Centre de Sciences Nucléaires et de Sciences de la Matière, Orsay) • +materialfrom: • F. Hammache, N. de Séréville, F. de Oliveira, V. Tatischeff, J. Margueron • 13 (IN2P3 & CEA) Laboratories: CENBG (Bordeaux), GANIL (Caen), LPC Caen, LPSC (Grenoble), Subatech (Nantes), LUPM (Montpellier), CSNSM (Orsay), IPNO (Orsay), LLR (Palaiseau), APC (Paris), Irfu/SPhN & Irfu/SAp (Saclay), IPHC (Strasbourg) • Collaboration with Institut National des Sciences de l'Univers (INSU) Laboratories: IAP (Paris), IRAP (Toulouse),....

  2. Nuclear Astrophysics • Motivations: • Source of stellar energy, stellar evolution • Origin of the elements (elemental and isotopic abundances) • Constraints on astrophysical models: Stellar surface abundances, nuclear gamma-ray emission, meteorites,… • Application in astroparticles, cosmological and fundamental physics:Cosmic rays, primordial nucleosynthesis, variation of constants,.… • An interdisciplinary domain by nature

  3. Origin of the Elements Already a long history[B2FH],also in France (in the 60’s) BBN, LiBeB • Primordial nucleosynthesis • Hydrogen burning • Helium burning • e-process (iron peak) • “x”-process (Li, Be, B): non- thermal nucleosynthesis • r-process (“rapid” n-capture) • s-process (“slow” n-capture) • p-process (proton rich) • Subsequent burning processes (12C+12C, 16O+12C, 16O+16O)

  4. Direct/indirect measurements Direct measurements Indirect measurements Model dependent Gamow window • Transfert reactions • 13C(7Li,t)17O [13C(,n)16O] • Resonantelastic diffusion • 12C(,)12C [12C(, )16O] • Coulomb dissociation • 6Li(*,)D [D(,)6Li] • Trojan Horse Method • D(7Li,)n [6Li(p,)4He] Very small cross sections 12C(,)16O, 14C(, )18O, 18O(, )22Ne et 22Ne(,)26Mg NUPPEC Long Range Plan Most important reactions Requiredprecision:10 %

  5. Primordial Nucleosynthesis • BBN calculation of of 4He, D, 3He, 7Liprimordial abundances at Planck baryonic density compared with observations. • Used to constrain new physics e.g. variation of “constants”, exotic particles,..., but... • The Lithium Problem: a factor of 3 7Lioverproduction • Observations? New physics? or • A nuclear solution ? New 7Be destruction channels(decays to 7Li)7Be+3He→10C*,7Be+α→11C* 7Li from 7Be decay

  6. Search for unknown states in 10Cand 11C • (3He,t) reaction on 10,11B targets • with the Split-pole magnetic spectrometer at the Orsay Tandem He shell 10B(3He,t)10C natB(3He,t)11C No additional state in 11C at ~ 7.8 MeV No obvious additional state in 10C at ~ 15 MeV • Rules out a nuclear solution [Hammache+ 2013] If present  total 590 keV (95% CL)

  7. Spectroscopy of 19Ne for 18F(p,)15O reaction (Explosive) Hydrogen burning: two examples Ganilexperiment[Mountford+ 2012] / predictions [Dufour & Descouvemont 2007] • The17O(p,)14N and 17O(p,γ)18F reactions (PAPAP, nowatDemocritos) 19F(3He,t)19Ne experiment at Orsay[IPNO, York, Barcelona] in 2014 ”on”/”off” resonnance[Chaffa+ 2005; 2007]

  8. Orsay 3/2+ Ecm Clark et al. 7.380 5/2- 7.166 5/2-  6.359 6.3561/2+ 13C+ Drotleff 93  Brune 93 5.9391/2- n Gamow peak 4.5543/2- 4.143 3.0551/2- 16O+n S=0.25 S=0.35 6.356 (1/2+) 6.356 (1/2+) 1/2 s-process neutron source: 13C(α, n)16O • s-process nucleosynthesis → half of the heavy elements • 90<A<209 low mass AGB stars 1-3 M (T108K) → neutron source 13C(,n)16O •  Split-Pole Orsay Tandem : 13C(7Li,t)17O 2? Sa? S(E)=E(E)exp(2) 1/2+ 0.0 5/2+ 17O The crucial role of the 6.356 MeV sub-threshold state is confirmed [Pellegriti+ 2008] Also applied to the most important reaction for He burning:12C(α, γ)15O[Oulebsir+ 2012]

  9. Study of 26Al(n,p)26Mg and26Al(n,α)23Na • 1.809 MeV from26Al observed (COMPTEL, INTEGRAL, RHESSI) • Origin: explosive Ne/C burning • Important: 26Al(n,p)26Mg & 26Al(n,α)23Na • Inelastic reaction:27Al(p,p')27Al* p & α in coincidence (DSSSDs) → Γp/Γ & Γα/Γ More than 30 new resonances above Snobserved with Split-Pole: [Benamara+ submitted] Opens up new possibilities e.g. Γp/Γfor30P(p,γ)

  10. r-process nucleosynthesis → the other half of the heavy elements • Presently most favored astrophysical origin: coalescence of two neutron stars r-process [S. Goriely, ULB, priv. comm.] • No r-process path : 1000’s nuclei and 10000’s rates (n-capture, lifetimes, fission, neutrinos,....) ⇒ massive input from theory (phenomenological→microscopic) • Spectroscopy, decay, masses, t1/2, Pn (ALTO, DESIR) • After post-acceleration ex : 130Cd(d,p)131Cd, et 134Sn(d,p)135Sn (SPIRAL 2)

  11. Non thermal reactions LiBeB from CNO spallation, γ from solar flares [511 keV, 56Fe*, 24Mg*, 20Ne*, 2.22 MeV, 12C*, 16O*; E/A= 2-100 MeV] and cosmic rays RHESSI Observations Total -ray emission cross section • γ-ray production cross sections: • Projectile+target = p, + 12C, 14N, 16O, Ne, 24Mg, Si, Fe and3He +16O, 24Mg [Benhabiles+ 2010] • Energies: 5 to 25/40 MeV (Orsay) → 66 MeV (2014) and 200 MeV (2015) [iTemba, Orsay, Algiers]

  12. Nuclear physics of dense matter Neutron stars are the ultimate states of massive stars (i.e. with 10<M/M<100) that exploded as SN. Nuclear conditions not reproducible in laboratory • Theory [U. van Kolck talk] : • EoSof dense matter? (Internal composition, stiffness, 2 M NS) • Transition from surface nuclei to core uniform matter via “pasta” ? • Superfluidity (cooling, “glitches”) • Electro-weak processes • Hyperonic matter Nucleonic matter Strange-quark matter Exotic hadronic matter • Experiments: • nuclear masses, giant resonant modes, neutron-skin, pairing, beta-decay, radii,.... (GANIL-SPIRAL 2), hypernuclei,... Adapted from Demorest et al. (2010)

  13. Other important activities in France • Theory (“diluted” matter): Shell Model, Microscopic (cluster) Model, Mass models, Hauser–Feshbach (TALYS),... • Evaluations: Masses, Thermonuclear rates • Cosmology: BBN, variation of constants • Gamma-ray astronomy: • Observations (INTEGRAL, RHESSI): solar flares, (novae) • Instrumentation: next generation of Compton Telescope • (Micro-)meteorites • Collection: Antartica or from space missions • Extinct radioactivities (→formation of the solar system)

  14. Present and future instruments • GANIL-SPIRAL1/2 [F. de Oliveira] • Tandem-ALTO [D. Verney] • ANDROMEDE (Orsay): 1 to 4 MVVan de Graaffand 12C + 12C reaction • CACAO (Orsay): Radioactive target production facillity (e.g. 60Fe, 26Al, 44Ti) • Laser MegaJoule (Bordeaux): screening studies, reaction rates. [Jiang+ 2010]

More Related