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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.
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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),....
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
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)
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 %
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
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)
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]
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 (T108K) → 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]
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)
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)
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]
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)
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)
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]