Gianluca Imbriani Physics Department of University of Naples Federico II, Italian National Institute of Nuclear Physics (INFN) and Joint Institute of Nuclear Astrophysics (JINA) Reaction rates for nucleosynthesys of ligh and intermediate-mass isotopes: 14 N(p,  ) 15 O, 15 N(p,  ) 16 O, 25 Mg(p,  ) 26 Mg, 17 O(p,  ) 18 F

LUNA I 50 kV LUNA II 400 kV LNGS Lab Voltage Range : kV Output Current: 1 mA Beam energy spread: 20 eV LUNA experimental set-ups Voltage Range : kV Output Current: 500  A Beam energy spread: 70 eV

CROSS SECTION LOG SCALE direct measurements EGEG Interaction energy E  (E) non-resonant resonance extrapolation needed ! many orders of magnitude ErEr non resonant process interaction energy E extrapolation direct measurement 0 S(E) LINEAR SCALE S(E)-FACTOR -E r sub-threshold resonance low-energy tail of broad resonance EGEG Most of the reactions of astrophysical interest happen via radiative capture. 3 He( ,  ) 7 Be, 14 N(p,  ) 15 O, 12 C( ,  ) 16 C... Problem of extrapolation p+p [keV] 3 He+ 3 He [keV] 3 He+ 4 He [keV] 7 Be+p [keV] 14 N+p [keV]

40 K 214 Bi 232 Th 40 K 214 Bi 232 ThE>4MeV Gran Sasso shielding: 3800 m w.e. RadiationLNGS/out muons neutrons Why going underground 1 st environmental radioactivity cosmic rays Therefore, the advantage of an underground environment is evident for high Q-value reactions such as 14 N(p,  ) 15 O, 15 N(p,  ) 16 O, 17 O(p,  ) 18 F, 25 Mg(p,  ) 26 Al......

Why going underground 2 nd HpGe spectrum E cm = 230keV «light» Pb shielding EPJA 25(2005) 14 N(p,  ) 15 O - EPJA 25(2005) 11 B(p,  ) 12 C Beam induced background

Solar neutrinos: 3 He( 3 He, 2p) 4 He, 3 He( ,  ) 7 Be, 14 N(p,  ) 15 O Big Bang nucleosynthesis: 2 H(p,  ) 3 He, 3 He( ,  ) 7 Be, 4 He(d,  ) 6 Li Age of Globular Clusters and C production in AGB: 14 N(p,  ) 15 O Light nuclei nucleosynthesis - 17 O/ 18 O abundaces, F origin, 26 Al  -ray in the Galaxy, 26 Mg excess....: 15 N(p,  ) 16 O, 17 O(p,  ) 18 F(  + ) 18 O, 25 Mg(p,  ) 26 Al(  + ) 26 Mg LUNA program: astrophysical motivation

pp-chain CNO Turn Off luminosity CNO cycle pp chain the onset of the CNO 12 C 13 N (p,  6  10 9 y 14 N (p,  1  10 9 y 15 O (p,  2  y 13 C e + 10 m 15 N e + 2 m CN 17 F (p,  17 O e + 64 s NO 16 O (p,  1  10 8 y (p,  (p,  18 F (p,  18 O e m (p,  CN Q eff = MeV NO Q eff = MeV 14 N(p,  ) 15 O is the bottleneck of the cycle, therefore the initial abundance of C, N, O is, mostly, converted in 14 N!! 14 N(p,  ) 15 O: Age of Globular Clusters

12 C 13 N (p,  6  10 9 y 14 N (p,  1  10 9 y 15 O (p,  2  y 13 C e + 10 m 15 N e + 2 m CN 17 F (p,  17 O e + 64 s NO 16 O (p,  1  10 8 y (p,  (p,  18 F (p,  18 O e m (p,  CN Q eff = MeV NO Q eff = MeV 14 N(p,  ) 15 O is the bottleneck of the cycle, therefore the initial abundance of C, N, O is, mostly, converted in 14 N!! Problem between observation and stellar models: observed over-production of all chemical elements above C by a factor of 2. The smaller the 14 N(p,γ ) 15 O rate, the larger is the amount of 12 C and metals, which will pollute the interstellar medium. 14 N(p,  ) 15 O: Yield production of 12 C in AGB

14 N(p,  ) 15 O: LUNA results E x (keV) E CM (keV) Q = N + p 15 O 7540 HpGe spectrum E cm =110keV BGO spectrum E cm =70keV PhLB 591(2004), EPJA 25(2005), PRC 78 (2008) NuPhyA 779(2006), NuPhyA 779(2006), PhLB, 634(2006)

14 N(p,  ) 15 O: S(0) and reaction rate LUNA/NACRE

Stellar calculation done with the FRANEC code The age of the oldest Globular Clusters should be increased by about Gyr. The lower limit to the Age of the Universe is 14 ± 1 Gyr. In good agreement with the precise detrmination of WMAP. G. Imbriani, et al., A&A 420(2004) With 14 N(p,γ) 15 O rate = ½ of NACRE better agreement between observation and calculation. 14 N(p,  ) 15 O: astrophysical consequences

Ground state transition 6.79MeV state transition 6.17MeV state transition Data from Schroeder, LENA and LUNA Adopted here S(0) = 1.66 ± % uncertainty Extrapolation toward lower energy

Solar neutrinos: 3 He( 3 He, 2p) 4 He, 3 He( ,  ) 7 Be 14 N(p,  ) 15 O Big Bang nucleosynthesis: 2 H(p,  ) 3 He, 3 He( ,  ) 7 Be, 4 He(d,  ) 6 Li Age of Globular Clusters and C production in AGB : 14 N(p,  ) 15 O Light nuclei nucleosynthesis - 17 O/ 18 O abundaces, F origin, 26 Al  -ray in the Galaxy, 26 Mg excess....: 15 N(p,  ) 16 O, 17 O(p,  ) 18 F(  + ) 18 O, 25 Mg(p,  ) 26 Al(  + ) 26 Mg, H-shell

12 C 13 N (p,  6  10 9 y 14 N (p,  1  10 9 y 15 O (p,  2  y 13 C e + 10 m 15 N e + 2 m CN 17 F (p,  17 O e + 64 s NO 16 O (p,  1  10 8 y (p,  (p,  18 F (p,  18 O e m (p,  Q=12127 keV 15 N(p,   ) 16 O 15 N(p,  4.4MeV ) 12 C 15 N(p,  )/(p,  ) ~ 1000 E x (keV) JJ N+p 16 O 16 O level scheme Q = keV N(p,  )/(p,  ): first branch of the CNO cycle

We measured the cross section in a wide energy window: MeV > E > 0.8 MeV KN 3.5 Notre Dame + HpGe clover detector; MeV > E > 0.3 MeV JN 1 Notre Dame + HpGe clover detector; MeV > E > 0.12 MeV 400 LUNA + HpGe detector. We used TiN deposited 50 and 150 nm targets Ta backing 45°, produced in Karlsruhe N(p,  ) 16 O LUNA & ND experimental set up

15 N(p,  ) 16 O LUNA & ND reults The leakage from CN to NO reduces of a factor 2: every about 2000 cycles of the main CN cycle, one goes to NO cycle. Before every 1000 cycles was the value recommended by the NACRE compilations (Angulo et al., 1999) KN ND JN ND LUNA P.J. Le Blanc, et al., PRC 82 (2010)

E x (keV) JJ Mg+p 26 Al 26 Al level scheme Q = 6306 keV Al 0 26 Al m 1809 E x (keV) 26 Mg  - ray 1.8 MeV  Signature of 26 Mg production during the Hydrogen burning (RGB, AGB) 26 Mg excess in meteorites Evidence that 26 Al nucleosynthesis is still active (WR stars, SN and NOVAE) T ½ = y << galactic time scale 24 Mg (p,  27 Al (p,  27 Si (p,  e + 4 s 26Al 26 Mg (p,  e + 6 s 25 Mg 25 Al (p,  e + 7 s (p,  25 Mg(p,  ) 26 Al – Astrophysical motivations

No direct strength resonance data (level structure derived from the single particle transfer reaction: 25 Mg( 3 He,d) 26 Al) -26 Q Al 0 (t 1/2 = 7·10 5 y) 26 Al m (t 1/2 = 6s) (4 + ) Al Novae explosive Burning (T 9 >0.1) AGB or W-R Stars (T 9 ~0.05) E x (keV) JJ E CM (keV)  Mg 25 Mg+p isomeric state High efficiency (about 50%) – Low resolution set-up  -ray Spectroscopy with 4  BGO + solid target  -ray Spectroscopy with HPGe  High resolution - Low efficiency high energy) + solid LUNA measurements

25 Mg(p,  ) 26 Al - HPGe spectra E R = 190 keV 75 C Iliadis et al, 1990

25 Mg(p,  ) 26 Al - HPGe spectra E R = 190 keV BR  0 = (75 ± 2) % 75 C  [eV] LUNA HPGe  [eV] LUNA BGO  [eV] Iliadis et al (9.0 ± 0.7)  (9.0 ± 0.8)  (7.4 ± 1.0)  10 -7

25 Mg(p,  ) 26 Al - BGO spectra E R = 92 keV The BGO  -ray total sum spectrum on the 92 keV 25 Mg(p,  ) 26 Al resonance (E p = 100 keV). 1.The shaded area  envinromental background 2.Thin solid line  25 Mg(p,  ) 26 Al simulation varying the primaries branchings. 3.Solid red line  total yield fit including background and simulation. Background run E p = 86.5 keV  [ eV] LUNA  [ eV] NACRE ind. 2.9 ± the lowest ever directly measured resonance strength E x (keV) JJ Mg+p 26 Al 26 Al level scheme Al 0 26 Al m BR  0 = ( ) %

25 Mg(p,  ) 26 Al - E R = 92 keV branchings Champagne et al. Nucl. Phys. A 402(1983) BR  0 = (81 ± 1 ) % BR  0 = ( ) %

25 Mg(p,  ) 26 Al - Astrophysical consequences LUNA results fully cover the temperature range of core massive main sequence stars (Wolf-Rayet) as well as the H-burning shell of RGB and AGB stars. 50 MK < T < 140 MK % larger factor 5 larger About factor 2 larger 50 MK < T < 140 MK In press in ApJ

25 Mg(p,  ) 26 Al - Astrophysical consequences WR stars: N A total factor 2 > NACRE and Iliadis N A isomeric factor 5 > NACRE and Iliadis  the expected production of 26 Al gs in stellar H- burning zones is lower than previously estimated. This implies a reduction of the estimated contribution of WR stars to the galactic production of 26 Al. Presolar grains originated in AGB stars Presolar grains originated in AGB stars: the most important conclusion is that the deep AGB extra- mixing, often invoked to explain the large excess of 26 Al in some O-rich grains, does not appear a suitable solution for 26 Al/ 27 Al> 10 −2. Mg-Al anti-correlation in Globular Clusters stars: Mg-Al anti-correlation in Globular Clusters stars: the substantial increase of the total reaction rate makes the Globular Cluster self-pollution caused by massive AGB stars a more reliable scenario for the reproduction of the Mg-Al anti-correlation. Preliminary, submitted to ApJ

17 O(p,  ) 18 F - Astrophysical motivation Classical Novae nucleosythesis (T= GK) Classical Novae nucleosythesis (T= GK): 1.production of light nuclei ( 17 O/ 18 O abundances....); 2. observation of 18 F  -ray signal (annihilation 511 keV).

17 O(p,  ) 18 F – LUNA experiment LUNA is directly investigating this energy window Broad resonaces DC component -·-·-·-·- Total 556 keV 767 keV Caciolli et al., submitted to EPJ A

17 O(p,  ) 18 F – On and off resonance spectra Off-Resonance On-Resonance To be published, courtesy of A. Formicola on behalf of the working group New transitions observed on resonance!

Total reaction Cross section measured between E cm ≈ 180 – 370 keV measured leading to a four-fold reduction in reaction rate uncertainty. Resonance Strength of E p =193 keV resonance measured within an uncertainty of 7%. ( ~ factor 2 higher accuracy). Preliminary Results 17 O(p,  ) 18 F – S-factor D. Scott et al. Accepted PRL

Total reaction Cross section measured between E cm ≈ 180 – 370 keV measured leading to a four-fold reduction in reaction rate uncertainty. Resonance Strength of E p =193 keV resonance measured within an uncertainty of 7%. ( ~ factor 2 higher accuracy). Preliminary Results 17 O(p,  ) 18 F – Reaction rate D. Scott et al. Accepted PRL _

17 O(p,  ) 18 F – The problem of the DC extrapolation towards lower energies C. Rolfs, Nucl. Phys. A217 (1973) 29 Kontos et al., submitted to PRC R-matrix analysis with AZURE code experiment performed in ND

LUNA 400 kV outlook 400 kV 2008 CNO CYCLE NeNa CYCLE 20 Ne 23 Na (p,  (p,  22 Na 22 Ne (p,  e + 3 yr 21 Ne 21 Na (p,  e + 22 s 12 C 15 N 13 C 14 N 13 N 15 O (p,  (p,  e + 6  10 9 y 1  10 9 y 2  y 2 m 1  10 8 y 10 m CN 16 O 17 O 17 F (p,  (p,  e + 64 s NO (p,  18 O 18 F (p,  e m (p,  19 F ( ,  (p,  24 Mg (p,  27 Al (p,  27 Si (p,  e + 4 s 26Al 26 Mg (p,  e + 6 s 25 Mg 25 Al (p,  e + 7 s MgAl CYCLE

The Luna Collaboration INFN, Laboratori Nazionali del Gran SassoA. Formicola, M. Junker INFN, Section of GenoaF. Cavanna, P. Corvisiero, P. Prati INFN, Section of MilanA. Guglielmetti (SP), D. Trezzi INFN, Section of NaplesA. Di Leva, G. Imbriani, E. Roca and F. Terrasi INFN, Section of PaduaC. Broggini, A. Caciolli, R. De Palo,R.Menegazzo INFN, Section of Roma 1C. Gustavino INFN, Section of TurinG. Gervino INAF, Teramo observatoryO. Straniero Ruhr-Universität Bochum, GermanyC. Rolfs, F. Strieder, H. P. Trautvetter Forschungszentrum Dresden-Rossendorf, GermanyM. Anders, D. Bemmerer, Z. Elekes Atomki Debrecen, HungaryZs. Fulop, Gy. Gyurky, E. Somorjai,T. Szucs The University of Edinburgh, UKM. Aliotta, T. Davinson, D. A. Scott

Accelerator Specifications U = 50 – 400 kV I  500  A for proton  E max = 0.07 keV Energy spread : 72eV Total uncertainty is  300 eV for E p =100  400keV Solid target + HPGe detector Gas target + BGO detector TiN (1/(1.08 ± 0.05)) targets 14 N(p,  ) 15 LUNA

Natural and enriched evaporated targets on Ta backing, starting from MgO powder Target study and normalization procedure Oxygen content determination via RBS on natural Mg target. Using a natural target with known Oxygen content and stoichiometry we measured of 24,25,26 Mg(p,  ) 25,26,27 Al at E cm = 214, 304, and 326 keV resonances with → HPGe 42 cm) and BGO setup → normalization for low-energies 

400 kV 2006 p + p  2 H + e + + [0.27 MeV] p + e - + p  2 H + [1.44 MeV] 2 H + p  3 He +  3 He + 3 He  4 He + 2p 3 He + 4 He  7 Be +  3 He + p  4 He + e Be + e -  7 Li + [0.81 MeV] 7 Be + p  8 B +  7 Li + p  8 Be 8 B  8 Be + e + + [6.80 MeV] 8 Be  2 4 He 8 Be  2 4 He 0.11%99.89% LUNA program: pp chain 99.75%0.25% 86%14% CHAIN III Q eff = MeV CHAIN II Q eff = MeV CHAIN I Q eff = MeV CHAIN IV Q eff = MeV 2·10 -5 % 50 kV kV 1999

LUNA program: CNO and MgAl chains 24 Mg (p,  27 Al (p,  27 Si (p,  e + 4 s 26Al 26 Mg (p,  e + 6 s 25 Mg 25 Al (p,  e + 7 s 400 kV kV kV kV 2008

E ~ kT nuclear well V rrnrn T ~ 15x10 6 K  E = kT ~ 1 keV E C = 550 keV during quiescent burnings: kT << E c reactions occur through TUNNEL EFFECT projectile E C ~ z 1 z 2 z 1 z 2 Example z 1 =p and z 2 =p (e.g. in the Sun) Charged particle reaction in stars reaction Coulomb barrier (keV) E G (keV) p + p  + 12 C O + 16 O

HpGe spectrum E cm = 230keV BGO spectrum E cm = 140keV G. Imbriani, et al., EPJA 25(2005) D. Bemmer, et al. NuPhyA 779(2006) 14 N(p,  ) 15 O:  -spectra Solid target + HPGe detector Gas target + BGO detector E x (keV) E CM (keV) Q = N + p 15 O 7540

Lowest energy HpGe spectrum E cm =110keVLowest energy BGO spectrum E cm =70keV A. Formicola et al., PhLB 591(2004) G. Imbriani, et al., EPJA 25(2005) M. Marta et al., PRC 78 (2008) D. Bemmer, et al. NuPhyA 779(2006) Lemut, et al. PhLB, 634(2006) 14 N(p,  ) 15 O:  -spectra and S(0)

LUNA/NACRE 14 N(p,  ) 15 O: reaction rate E x (keV) E CM (keV) Q = N + p 15 O 7540