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Alain Coc CSNSM (Centre de Sciences Nucléaires et de Sciences de la Matière, Orsay) +material from: F. Hammache, N. de Séréville, F. de Oliveira, V. Tatischeff, J. Margueron Nuclear Astrophysics in France 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),....
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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 Nuclear Astrophysics
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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 ( 12 C+ 12 C, 16 O+ 12 C, 16 O+ 16 O) Origin of the Elements Already a long history [B 2 FH], also in France (in the 60’s) BBN, LiBeB
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Direct measurements Very small cross sections Indirect measurements Transfert reactions 13 C( 7 Li,t) 17 O [ 13 C( , n) 16 O] Resonant elastic diffusion 12 C( , ) 12 C [ 12 C( , ) 16 O] Coulomb dissociation 6 Li( *, )D [D( , ) 6 Li] Trojan Horse Method D( 7 Li, )n [ 6 Li(p, ) 4 He] Model dependent Gamow window Direct/indirect measurements 12 C( , ) 16 O, 14 C( , ) 18 O, 18 O( , ) 22 Ne et 22 Ne( , ) 26 Mg NUPPEC Long Range Plan Most important reactions Required precision: 10 %
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BBN calculation of of 4 He, D, 3 He, 7 Li primordial 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 7 Li overproduction Observations? New physics? or A nuclear solution ? New 7 Be destruction channels (decays to 7 Li) 7 Be+ 3 He→ 10 C*, 7 Be+α→ 11 C* Primordial Nucleosynthesis 7 Li from 7 Be decay
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He shell No obvious additional state in 10 C at ~ 15 MeV nat B( 3 He,t) 11 C No additional state in 11 C at ~ 7.8 MeV If present total 590 keV (95% CL) Rules out a nuclear solution [Hammache+ 2013] ( 3 He,t) reaction on 10,11 B targets with the Split-pole magnetic spectrometer at the Orsay Tandem Search for unknown states in 10 C and 11 C 10 B( 3 He,t) 10 C
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(Explosive) Hydrogen burning: two examples Spectroscopy of 19 Ne for 18 F(p, ) 15 O reaction Ganil experiment [Mountford+ 2012] / predictions [Dufour & Descouvemont 2007] 19 F( 3 He,t) 19 Ne experiment at Orsay [IPNO, York, Barcelona] in 2014 The 17 O(p, ) 14 N and 17 O(p,γ) 18 F reactions (PAPAP, now at Democritos) ”on”/”off” resonnance [Chaffa+ 2005; 2007]
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s-process nucleosynthesis → half of the heavy elements 90<A<209 low mass AGB stars 1-3 M (T 10 8 K) → neutron source 13 C( ,n) 16 O Split-Pole Orsay Tandem : 13 C( 7 Li,t) 17 O Drotleff 93 Brune 93 Orsay 3/2 + Gamow peak Clark et al. 6.356 (1/2 + ) S =0.25S =0.35 1/2 + The crucial role of the 6.356 MeV sub-threshold state is confirmed [Pellegriti+ 2008] S(E)=E (E)exp(2 ) 1/2 s-process neutron source: 13 C(α, n) 16 O Also applied to the most important reaction for He burning: 12 C(α, γ) 15 O [Oulebsir+ 2012] 2 ? S ? 13 C+ 6.359 6.356 1/2 + 5.939 1/2 - 16 O+n 4.554 3/2 - 4.143 3.055 1/2 - 7.166 5/2 - 7.380 5/2 - nn E cm 0.0 5/2 + 17 O
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Study of 26 Al(n,p) 26 Mg and 26 Al(n,α) 23 Na 1.809 MeV from 26 Al observed (COMPTEL, INTEGRAL, RHESSI) Origin: explosive Ne/C burning Important: 26 Al(n,p) 26 Mg & 26 Al(n,α) 23 Na Inelastic reaction: 27 Al(p,p') 27 Al* More than 30 new resonances above S n observed with Split-Pole: p & α in coincidence (DSSSDs) → Γ p /Γ & Γ α /Γ Opens up new possibilities e.g. Γ p /Γ for 30 P(p,γ) [Benamara+ submitted]
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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 : 130 Cd(d,p) 131 Cd, et 134 Sn(d,p) 135 Sn (SPIRAL 2) r-process r-process nucleosynthesis → the other half of the heavy elements Presently most favored astrophysical origin: coalescence of two neutron stars [S. Goriely, ULB, priv. comm.]
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Non thermal reactions LiBeB from CNO spallation, γ from solar flares [ 511 keV, 56 Fe*, 24 Mg*, 20 Ne*, 2.22 MeV, 12 C*, 16 O*; E/A= 2-100 MeV ] and cosmic rays RHESSI Observations γ-ray production cross sections: Projectile+target = p, + 12 C, 14 N, 16 O, Ne, 24 Mg, Si, Fe and 3 He + 16 O, 24 Mg [Benhabiles+ 2010] Energies: 5 to 25/40 MeV (Orsay) → 66 MeV (2014) and 200 MeV (2015) [iTemba, Orsay, Algiers] Total -ray emission cross section
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Nuclear physics of dense matter Adapted from Demorest et al. (2010) Nucleonic matter Exotic hadronic matter Strange- quark 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] : EoS of 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 Experiments: nuclear masses, giant resonant modes, neutron-skin, pairing, beta-decay, radii,.... (GANIL- SPIRAL 2), hypernuclei,...
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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)
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Present and future instruments GANIL-SPIRAL1/2 [F. de Oliveira] Tandem-ALTO [D. Verney] ANDROMEDE (Orsay): 1 to 4 MV Van de Graaff and 12 C + 12 C reaction CACAO (Orsay): Radioactive target production facillity (e.g. 60 Fe, 26 Al, 44 Ti) Laser MegaJoule (Bordeaux): screening studies, reaction rates. [Jiang+ 2010]
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