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NuPECC - Milan 9 2012 Present and future of Laboratory Underground Nuclear Astrophysics Alba Formicola - Status of the D(, ) 6 Li measurement -Status of.

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Presentation on theme: "NuPECC - Milan 9 2012 Present and future of Laboratory Underground Nuclear Astrophysics Alba Formicola - Status of the D(, ) 6 Li measurement -Status of."— Presentation transcript:

1 NuPECC - Milan Present and future of Laboratory Underground Nuclear Astrophysics Alba Formicola - Status of the D(, ) 6 Li measurement -Status of the 17 O(p, ) 18 F measurement -Status of the LUNA MV project and plans for the future

2 NuPECC - Milan BBN : Production of the lightest elements (D, 3 He, 4 He, 7 Li, 6 Li) in the first minutes after the Big Bang The case of 6 Li It has the next-highest predicted primordial abundance after D, 3 He, 4 He and 7 Li It has been found in non negligible quantities in very old low metallicity halo stars unexpectedly high amount (2-3 orders of magnitude compared to available BBN network predictions - NACRE) The primordial abundance is determined by the rate of two reactions: D(a, ) 6 Li which produces practically all the 6 Li 6 Li(p, ) 3 He which destroys 6 Li sufficiently well known Theoretical estimates in the region of interest differ by 1-2 orders of magnitude

3 NuPECC - Milan Experimental set-up to study the D( ) 6 Li reaction D(α,α)D Rutherford scattering D(D,n) 3 He reaction also D(D,p)t occurs with similar cross section monitoring of neutron production Beam induced background 4 He beam (I ~300 A) on a windowless D 2 gas target (P=0.3mbar) beam current measurement by calorimeter HPGe detector for γ detection

4 (n,n ) reaction on the surrounding materials (Pb, Ge, Cu). -ray background in the D(a, ) 6 Li RoI (~1.6 MeV) Direct measurement of the D( ) 6 L cross section at astrophysical energies The next beam time is scheduled for March and April 2012 measurement with an AmBe neutron source to compare with simulation results further work to understand the background in the γ-detector

5 17 O+p is of paramount importance for understanding hydrogen-burning in different stellar environments: Red Giants Novae stars Massive Stars Asymptotic Giant Branch (AGB) Astrophysical motivation to study the 17 O(p,γ) 18 F reaction Hot-CNO Cycle Rolfs et al. Nuc. Phys. A (1973) – Fox et al. Phys. Rev. C 71, (2005) – 193 keV res. meas. : ωγ 193 = (1.2±0.2)×10 -6 eV Chafa et al. Phys. Rev. C 75, (2007) - Activation meas. : ωγ 193 = (2.2±0.4)×10 -6 eV Newton et al. Phys. Rev. C 81, (2010): cross section measurements 17 O 18 F 14 N 13 C 13 N 12 C 15 N 16 O 18 O 15 N 17 F (p ) (p, γ ) (β+ν)(β+ν)

6 NuPECC - Milan Experimental setup to study the 17 O(p,γ) 18 F reaction Proton energy range covered : keV with an average current I ~ 300 μA Enriched 17 O targets Activation and Prompt on Ta backings Gamma measurements 18 O(p,γ) 19 F target profile

7 NuPECC - Milan On resonance spectra of the 17 O(p,γ) 18 F reaction 18 F 17 O+p E p = 193 keV E x (keV) R -> 3791 R -> 2101 R -> 3133 R -> 1080 R ->

8 NuPECC- Milan In a very low background environment such as LNGS, it is mandatory not to increase the neutron flux above its average value α beam intensity: 200 µA Target: 13 C, at/cm 2 (99% 13 C enriched) Beam energy(lab) 0.8 MeV α beam intensity: 200 µA Target: 22 Ne, at/cm 2 Beam energy(lab) 1.0 MeV from α beam intensity: 200 µA Target: 13 C, at/cm 2 ( 13 C/ 12 C = ) Beam energy(lab) 3.5 MeV Maximum neutron production rate : 2000 n/s Maximum neutron energy (lab) : 5.6 MeV The LUNA MV project 12 C( ) 16 O the Holy Grail from Nobel Lecture 1993 by William Fowler Higher energy machine 3.5 MV single ended positive ion accelerator

9 Next-generation underground laboratory for Nuclear Astrophysics: …. call to the European Nuclear Astrophysics community for a wider collaboration in support of the next- generation underground laboratory. To state your interest to contribute to any of the Work Packages under International Collaboration WP1: Accelerator + ion source WP2: Gamma detectors WP3: Neutron detectors WP5: Solid targets WP6: Gas target WP7: Simulations WP8: Stellar model calculations Representatives: Aliotta Marialuisa, Luis Fraile, Zsolt Fulop, Alessandra Guglielmetti


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