I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY 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 L ABORATORY 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 L ABORATORY s-process nucleosynthesis Two components were identified and connected to stellar sites: Main s-process ~90<A<210Weak s-process A<~90 TP-AGB stars 1-3 M ⊙ massive stars > 8 M ⊙ core He-burning shell C-burning 3-3.5·10 8 K ~1·10 9 K kT=25 keV kT=90 keV 10 6 cm cm Ne( ,n) 25 Mg shell H-burning He-flash 0.9·10 8 K 3-3.5·10 8 K kT=8 keV kT=25 keV cm cm C( ,n) 16 O 22 Ne( ,n) 25 Mg ARUNA 2014

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY ARUNA Ne( ,n) 25 Mg Status of direct measurements 22 Ne(α,n) 25 Mg

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY ARUNA 2014 HI  S Longland et al Mg( ,  ) E R = (1) keV, J π = 1 + cannot contribute to the n-channel 26 Mg ( ,n) 1) 2) 3) 4) 5)

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY ARUNA 2014 ( ,  ’) and ( 6 Li,d) at RCNP Osaka 22 Ne( 6 Li,d) 26 Mg(α,α’)

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY ARUNA 2014 Status 13 C(α,n) 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, (2008) Contribution from below threshold at -3 keV has been evaluated with Trojan Horse Method. M. La Cognata et al.

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY CASPAR ARUNA 2014 Compact Accelerator System to Perform Astrophysics Research At the Sanford Underground Research Facility (USA/SD)

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY CASPAR ARUNA 2014 Proton and Helium beam from a 200 kV to 1MV electrostatic accelerator Bombard an extended 22 Ne gas target surrounded by 3 He neutron detector Complementary to LUNA research program Different energy range Helium beam allowed

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY CASPAR to neutron background of surface S. Falahat et al., NIMA 700 (2013) 53 Low internal background 3 He tube ARUNA 2014

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY CASPAR Collaboration between: University of Notre Dame South Dakota School of Mines and Technology Colorado School of Mines Aggressive time line: Installation completed by mid-2015 Will be operational before any new underground accelerator program in the world JN 1MV accelerator (H and He beams) Refurbishment and control system Neutron detector Technical support Gas target for isotopically enriched gas Local support In charge of operation ARUNA 2014 Construct the laboratory Partially fund the installation of CASPAR

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY CASPAR Science goals Neutron Sources and Neutron Poisons 13 C(α,n) 16 O, 22 Ne(α,n) 25 Mg, 22 Ne(α, γ ) 26 Mg, 17 O(α,n) 20 Ne, 17 O(α, γ ) 21 Ne Total program: (5-8 years) Preliminary measurement at Notre Dame and elsewhere to optimize underground studies ARUNA 2014 Other science goals Other nuclear astrophysics questions Reaction of interest for fusion energy and plasma physics

I NSTITUTE FOR S TRUCTURE AND N UCLEAR A STROPHYSICS N UCLEAR S CIENCE L ABORATORY CASPAR – SDSM&T: D. Wells + ??? – CSM: U. Greife – UND: H.-S. Jung, D. Robertson, K. Setoodehnia, M. Wiescher – UNC A. Champagne Collaborations ARUNA 2014