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LUNA and the Sun. Men in pits or wells sometimes see the stars…. Aristotle. Nuclear Burning in Stars s (E star ). Carlo Broggini, INFN-Padova. s ( E ) = S(E) e –2 ph E -1. 2 ph = 31.29 Z 1 Z 2 m/E. . Reaction Rate(star) . F (E) s (E) dE. m = m 1 m 2 / ( m 1 + m 2 ).
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LUNA and the Sun Men in pits or wells sometimes see the stars…. Aristotle • Nuclear Burning • in Stars • s(Estar) Carlo Broggini, INFN-Padova s(E) = S(E) e–2phE-1 2ph = 31.29 Z1Z2m/E Reaction Rate(star) F(E) s(E) dE m = m1m2 / (m1+m2) Gamow Peak Extrap. Meas. s Maxwell Boltzmann s
LUNA1 ( 50kV) LUNA2 (400kV) 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 Voltage Range : 1 - 50 kV Output Current: 1 mA Beam energy spread: 20 eV Long term stability (8 h): 10-4 Terminal Voltage ripple: 5 10-5
p + p d + e+ + ne d + p 3He + g pp chain 84.7 % 13.8 % 3He +3He a+2p 3He +4He 7Be + g 0.02% 13.78 % 7Be +p 8B + g 7Be+e- 7Li + g +ne 7Li +p a + a 8B 2a + e++ ne
3He(,g)7Be Q=1.6 MeV • Solar Neutrinos:7Be,8B • BBN 7Li • Cross section from prompt gamma down to • 90 keV (CM energy) using 4He beam on 3He • target • Activation via off-line radioactive decay • measurements of the 7Be atoms collected • in the beam catcher • All with a final error < 5 %
s of3He(,g)7Be down to 93keV • 7Be ≈ prompt g • S34(0) = 0.560 0.017 keV barn • ΔΦ(B) reduced from 12% to 10% • ΔΦ(Be) reduced from 9.4% to 5.5% (C. Pena Garay) Borexino-Kamland
14N(p,g)15O Q=7.3 MeV E<1.2 MeV E<1.7 MeV • F S1,14 cno 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 Low energy: gas target + BGO 7556 1/2+ 7297 14N(p,g)15O 7276 7/2 + 14N+p 6859 5/2 + -21 6793 3/2 + - 504 6176 3/2 - 5241 5/2 + 5183 1/2 + “High” energy: solid target + HpGe 15O 0 1/2 - beam energy 90 keV gamma spectrum of 14N(p,g)15O at 140 keV beam energy
cno from the Sun Globular cluster age C yield in AGB stars St(0)=1.61±0.18 keV b ‘clover’ study of the capture to the ground state:error on St(0)= ±0.13 cno from the Sun solar core metallicity
Rich program ofNuclear Astrophysics: 25Mg(p,g)26Al Q=6.3 MeV (almost completed) 15N(p,g)16O Q=12.13 MeV (already started) 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 ............
LUNAhas shown that it is possible to measure • s(Estar): 3He (3He,2p)4He, 2H(p,g)3He • 3He (3He,2p)4He: sdown to 16 keV • no resonance within the solar Gamow Peak sdown to 93 keV • 3He(,g)7Be: 7Be ≈ promptg ΔΦ(Be)reduced from9.4% to 5.5% • 14N(p,g)15O: s down to 70 keV (T=60 T6) • cnoreduced by 2 with 8% error core metallicity • Globular cluster age increased by 0.7-1 Gy • Higher C yield in AGB stars
LUNA INFN - Laboratori Nazionali del Gran Sasso D.Bemmerer,R.Bonetti,C.Broggini,F. Confortola,P.Corvisiero,H.Costantini, Z.Elekes, A.Formicola, Z. Fülöp, G.Gervino,A.Guglielmetti, C.Gustavino, G. Gyurky, G. Imbriani, M.Junker, A.Lemut, B.Limata, V.Lozza,M.Marta,R.Menegazzo, P.Prati, V.Roca, C.Rolfs, M.Romano, C.RossiAlvarez, O.Straniero,F.Strieder, E.Somorjai,F.Terrasi,H.P.Trautvetter •INFN : Genova, LNGS, Milano, Napoli, Padova, Torino •Inst.Physik mit Ionenstrahlen, Ruhr-Universität Bochum •Forschungszentrum Dresden-Rossendorf •Atomki Debrecen