Post on 21-Jan-2016
(E) = S(E) e–2E-1
2 mmmm
Reaction Rate(star) (E) (E) dE
Gamow Peak
MaxwellBoltzmann
Extrap. Meas.
Carlo Broggini, INFN-Padova
Stellar Energy+Nucleosynthesis
(Estar) with Estar << ECoulomb Hydrogen Burning
LUNA, the Sun and the other stars
S(E)
Laboratory for UndergroundNuclear 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+ + e
d + p 3He +
3He +3He +2p 3He +4He 7Be +
7Be+e- 7Li + +e 7Be + p 8B +
7Li + p 8B 2 + e++ e
pp chain
6% prediction of 7Be solar neutrino flux, opacity dominanterror source
Proto-stars and BBN
In search of the resonance
85%
3He (3He,2p)4He
Q = 12.86 MeV
min= 0.02 pb
Epmax= 10.7 MeV
Suppression of 7Be
and 8B ?
14N(p,)15O
Q=7.3 MeV
cno
S1,14
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)
E<1.20 MeV
E<1.73 MeV
- 504
-21
278
1414N+pN+p
729772977556
7276
68596793
6176
5241
5183
01515OO
1/2 +
7/2 +
5/2 +
3/2 +
3/2 -
5/2 +
1/2 +
1/2 -
“High” energy: solid target + HpGe
gamma spectrum of 14N(p,)15O at 140 keV beam energy
14N(p,)15O
Low energy: gas target + BGO
beam energy 90 keV
*½cno from the Sun * Globular Cluster age +1Gy * more C at the surface of
AGB
From a measurement of cno from the Sun
St(0)=1.61±0.18 keV b
New study with a ‘clover’ detector of the capture to the ground state
St(0)=1.57±0.13 keV b
Metallicity of the Sun core (C+N)Photosphere and core metallicity equal?
2005: solar composition problem
2H(α,)6Li Q=1.47 MeV
15N(p,)16O Q=12.13 MeV
17O(p,)18F Q=5.6 MeV
23Na(p,)24Mg Q=11.7 MeV
22Ne(p,)23Na Q=8.8 MeV
18O(p,)19F Q=8.0 MeV
25Mg(p,)26Al Q=6.3 MeV
LUNA beyond the Sun: isotope production in the hydrogen burning shell of AGB stars (~30-100 T6), Nova nucleosynthesis (~100-500 T6) and BBN
............
down to 70 keV reduced by factor 2
down to 92 keV resonance: the lowest ever directly measured resonance strength
12C(,)16O the ‘Holy Grail’ of nuclear astrophysics
13C(,n)16O, 22Ne(,n)25Mg the stellar sources of the neutrons responsible for the S-process
(,) on 14N, 15N, 18O……
LUNA beyond the Hydrogen burning: 3.5 MV accelerator @Gran Sasso
- Letter of Intent to LNGS 2007
- Round Table @LNGS 2/2011 http://luna.lngs.infn.it/
Proposal
3He(,)7Be:
14N(p,)15O: down to 70 keV
cno reduced 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
3He (3He,2p)4He: down to 16 keV no resonance within the solar Gamow Peak
ΔΦ(Be) reduced to 6%
7Be ≈ prompt
15N(p,)16O: down to 70 keV, reduced by 2 25Mg(p,)26Al: first measurement of the 92 keV resonance Future: Hydrogen burning in shell, Helium burning
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
LUNALUNA
3He(,)7Be
Solar Neutrinos: 7Be,8B
S34
BBN 7Li
Q=1.6 MeV
down to 93 keV 7Be ≈ prompt
SS3434(0) = 0.567 (0) = 0.567 0.018 keV barn 0.018 keV barn
ΔΦ(B) reduced to 11%
ΔΦ(Be) reduced to 6% (dominant error source:
opacity) Borexino
0,45
0,47
0,49
0,51
0,53
0,55
0,57
80 100 120 140 160 180
Ecm [keV]
S(E
) [k
eV b
]
activation-PRL+PRC
activation
on-line