Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY CASPAR An underground Accelerator Laboratory for Nuclear Astrophysics Manoel Couder University of Notre Dame I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY • Neutron sources for the s-process • CASPAR – Facility – Collaboration – Timeline ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY s-process nucleosynthesis Two components were identified and connected to stellar sites: Main s-process ~90<A<210 Weak s-process A<~90 TP-AGB stars 1-3 M⊙ shell H-burning 0.9·108 K kT=8 keV 107-108 cm-3 13C(a,n)16O massive stars > 8 M⊙ core He-burning shell C-burning 3-3.5·108 K ~1·109 K kT=25 keV kT=90 keV 106 cm-3 1011-1012 cm-3 22Ne(a,n)25Mg He-flash 3-3.5·108 K kT=25 keV 1010-1011 cm-3 22Ne(a,n)25Mg ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY 22Ne(a,n)25Mg Status of direct measurements 22Ne(α,n)25Mg 22Ne(α,n)25Mg ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY 26Mg(g, g) HIgS 26Mg(g,n) Longland et al. 2009 5) 4) 3) 2) 1) ER = 11153.5(1) keV, Jπ = 1+ cannot contribute to the n-channel ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY (a,a’) and (6Li,d) at RCNP Osaka 22Ne(6Li,d) 26Mg(α,α’) ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY Status 13C(α,n) Contribution from below threshold at -3 keV has been evaluated with Trojan Horse Method. M. La Cognata et al. Since the present technical possibilities appear to be exhausted, a reduction of the remaining uncertainty can probably only be achieved in an underground laboratory, where the cosmic-ray induced γ background can be avoided. M. Heil et al., Phys. Rev. C 78, 025803 (2008) ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY CASPAR Compact Accelerator System to Perform Astrophysics Research At the Sanford Underground Research Facility (USA/SD) ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY CASPAR Proton and Helium beam from a 200 kV to 1MV electrostatic accelerator Bombard an extended 22Ne gas target surrounded by 3He neutron detector Complementary to LUNA research program Different energy range Helium beam allowed ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY CASPAR 10-3 to 10-4 neutron background of surface Low internal background 3He tube S. Falahat et al., NIMA 700 (2013) 53 ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY CASPAR Collaboration between: University of Notre Dame South Dakota School of Mines and Technology Colorado School of Mines JN 1MV accelerator (H and He beams) Refurbishment and control system Neutron detector Technical support Local support In charge of operation ARUNA 2014 Aggressive time line: Installation completed by mid-2015 Will be operational before any new underground accelerator program in the world Gas target for isotopically enriched gas Construct the laboratory Partially fund the installation of CASPAR I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY CASPAR Science goals Neutron Sources and Neutron Poisons 13C(α,n)16O, 22Ne(α,n)25Mg, 22Ne(α,γ)26Mg, 17O(α,n)20Ne, 17O(α,γ)21Ne Total program: (5-8 years) Preliminary measurement at Notre Dame and elsewhere to optimize underground studies Other science goals • Other nuclear astrophysics questions • Reaction of interest for fusion energy and plasma physics ARUNA 2014 I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE LABORATORY Collaborations • CASPAR – SDSM&T: D. Wells + ??? – CSM: U. Greife – UND: H.-S. Jung , D. Robertson, K. Setoodehnia, M. Wiescher – Friends @ UNC A. Champagne ARUNA 2014