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LUNA, the Sun and the other stars. Stellar Energy+Nucleosynthesis. Hydrogen Burning. s (E star ) with E star << E Coulomb. Carlo Broggini, INFN-Padova. s ( E ) = S(E) e –2 ph E -1. m = m 1 m 2 / ( m 1 + m 2 ). 2 ph = 31.29 Z 1 Z 2 m/E. . Reaction Rate(star) . F (E) s (E) dE.
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LUNA, the Sun and the other stars • Stellar Energy+Nucleosynthesis • Hydrogen Burning • s(Estar) with Estar << ECoulomb Carlo Broggini, INFN-Padova s(E) = S(E) e–2phE-1 m = m1m2 / (m1+m2) 2ph = 31.29 Z1Z2m/E Reaction Rate(star) F(E) s(E) dE s Meas. Extrap. Gamow Peak S(E) Maxwell Boltzmann s
Laboratory for Underground Nuclear Astrophysics Voltage Range :50-400 kV Output Current: 1 mA (@ 400 kV) Absolute Energy error ±300 eV Beam energy spread: <100 eV Long term stability (1 h) : 5 eV Terminal Voltage ripple: 5 Vpp Ge detector
p + p d + e+ + ne d + p 3He + g pp chain 3He +3He a+2p 3He +4He 7Be + g 7Be +p 8B + g 7Be+e- 7Li + g +ne 7Li +p a + a 8B 2a + e++ ne Proto-stars and BBN 85% In search of the resonance 6% prediction of 7Be solar neutrino flux, opacity dominant error source
3He (3He,2p)4He Q = 12.86 MeV Epmax= 10.7 MeV Suppression of 7Be and 8B ? min = 0.02 pb
14N(p,g)15O Q=7.3 MeV E<1.20 MeV E<1.73 MeV • F S1,14 cno • Globular Cluster Age S(0)=3.5-1.6+0.4 keV b (Ad98) S(0)=3.2-0.8+0.8 keV b (An99)
278 “High” energy: solid target + HpGe 7556 1/2+ 7297 14N(p,g)15O 7276 7/2 + gamma spectrum of 14N(p,g)15O at 140 keV beam energy 14N+p 6859 5/2 + -21 6793 3/2 + - 504 6176 3/2 - 5241 5/2 + 5183 1/2 + Low energy: gas target + BGO 15O 0 1/2 - beam energy 90 keV
St(0)=1.61±0.18 keV b *½cno from the Sun * Globular Cluster age +1Gy * more C at the surface of AGB 2005: solar composition problem New study with a ‘clover’ detector of the capture to the ground state St(0)=1.57±0.13 keV b From a measurement of cno from the Sun Metallicity of the Sun core (C+N) Photosphere and core metallicity equal?
LUNA beyond the Sun:isotope production in the hydrogen burning shell of AGB stars (~30-100 T6), Nova nucleosynthesis (~100-500 T6) and BBN sdown to70keVreducedby factor 2 15N(p,g)16O Q=12.13 MeV down to92keV resonance:the lowest ever directly measured resonance strength 25Mg(p,g)26Al Q=6.3 MeV 2H(α,g)6LiQ=1.47 MeV 17O(p,g)18F Q=5.6 MeV 18O(p,g)19F Q=8.0 MeV 22Ne(p,g)23Na Q=8.8 MeV 23Na(p,g)24Mg Q=11.7 MeV ............
LUNA beyond the Hydrogen burning: 3.5 MV accelerator @Gran Sasso 12C(a,g)16Othe ‘Holy Grail’ of nuclear astrophysics 13C(a,n)16O, 22Ne(a,n)25Mgthe stellar sources of the neutrons responsible for the S-process (a,g) on14N, 15N, 18O…… - Letter of Intent to LNGS 2007 - Round Table @LNGS 2/2011 http://luna.lngs.infn.it/ Proposal
3He (3He,2p)4He: sdown to 16 keV • no resonance within the solar Gamow Peak • 3He(,g)7Be: 7Be ≈promptg ΔΦ(Be) reducedto 6% • 14N(p,g)15O: s down to 70 keV • cnoreduced by 2 with 8% error Sun core metallicity • Globular cluster age increased by 0.7-1 Gy • More carbon at the surface of AGB stars • 15N(p,g)16O: s down to 70 keV, reduced by 2 • 25Mg(p,g)26Al: first measurement of the 92 keV • resonance • Future:Hydrogen burning in shell, Helium burning
LUNA INFN - Laboratori Nazionali del Gran Sasso D.Bemmerer,C.Broggini,A.Caciolli,P. Corvisiero,H.Costantini, Z.Elekes, A.Formicola, Z. Fülöp, G.Gervino,A.Guglielmetti, C.Gustavino, G. Gyurky, G. Imbriani, M.Junker, A.Lemut, M.Marta,C.Mazzocchi,R.Menegazzo, P.Prati, V.Roca, C.Rolfs, C.RossiAlvarez,E.Somorjai, O.Straniero,F.Strieder, F.Terrasi,H.P.Trautvetter •INFN : Genova, LNGS, Milano, Napoli, Padova, Torino •Inst.Physik mit Ionenstrahlen, Ruhr-Universität Bochum •Forschungszentrum Dresden-Rossendorf •Atomki Debrecen
3He(,g)7Be Q=1.6 MeV • Solar Neutrinos: 7Be,8B • F S34 • BBN 7Li
s down to 93 keV • 7Be ≈ prompt g • S34(0) = 0.567 0.018 keV barn • ΔΦ(B) reduced to 11% • ΔΦ(Be) reducedto 6% (dominant error source: opacity) Borexino