150 likes | 277 Views
Carlo Broggini, INFN-Padova. Neutrino cross sections for Astrophysics. Gamow Factor. Astrophysical Factor. Nuclear Burning in Stars s (E star ). s ( E ) = S(E) e –2 ph E -1. 2 ph = 31.29 Z 1 Z 2 m/E cm. m = m 1 m 2 / ( m 1 + m 2 ). . Reaction Rate(star) .
E N D
Carlo Broggini, INFN-Padova Neutrino cross sections for Astrophysics Gamow Factor Astrophysical Factor • Nuclear Burning • in Stars • s(Estar) s(E) = S(E) e–2phE-1 2ph = 31.29 Z1Z2m/Ecm m = m1m2 / (m1+m2) Reaction Rate(star) F(E) s(E) dE Extrap. Meas. Gamow Peak s Maxwell Boltzmann s
LUNA INFN - Laboratori Nazionali del Gran Sasso R.Bonetti, C.Broggini*,F.Confortola, P.Corvisiero,H.Costantini, J. Cruz, A.Formicola, Z. Fülöp, G.Gervino, A.Guglielmetti, C.Gustavino, G. Gyurky, G. Imbriani, A.P.Jesus, M.Junker, A.Lemut, R.Menegazzo, A.Ordine, P.Prati, V.Roca, D.Rogalla, C.Rolfs, M.Romano, C.RossiAlvarez, F.Schümann, O.Straniero,F.Strieder, E.Somorjai,F.Terrasi,H.P.Trautvetter, S.Zavatarelli •INFN : Genova, LNGS, Milano, Napoli, Padova, Torino •Inst.Physik mit Ionenstrahlen, Ruhr-Universität Bochum (GE) •Centro de Fisica Nuclear da Universidade de Lisboa (Portugal) •Atomki Debrecen (Hungary)
F Fn = 0.7m-2 h-1 310-6cm-2 s-1 luna
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 2004-2005 measured
3He (3He,2p)4He Q = 12.86 MeV Epmax= 10.7 MeV from the Sun min = 0.02 pb
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)
S 14,1 /5 S 14,1 x5 Standard CF88
“High” energy: solid target + HpGe gamma spectrum of 14N(p,g)15O at Ep=140 keV
14N(p,g)15O g.s. transition S gs(0)=1.55±0.34 keV b (Schr87) S gs(0)=0.08+0.13–0.06 keV b (Ang01) S gs(0)=0.25±0.06 keV b (LUNA) s S tot(0)=1.7±0.1 ±0.2 keV b (LUNA) ~ 0.5 cno ~ 0.5 Globular cluster age: +0.7-1 Gy
Low energy: gas target + BGO Ebeam = 80 keV
LUNA has shown that it is s(Estar) possible to measure from he Sun • Past: 3He (3He,2p)4He • Present: 14N(p,g)15O ,Globular cluster age cno • Future: 3He(,g)7Be the Sun
D(p,g)3He Q = 5.5. MeV • D abundance • Proto-stars • Big-bang
14N(p,g)15O 6.79 MeV transition S 6.79(0)=1.41±0.02 keV b (Schr87) S 6.79(0)=1.63±0.17 keV b (Ang01) S 6.79(0)=1.35±0.05±0.08 keV b (LUNA)