I N S T I T U T E F O R S T R U C T U R E A N D N U C L E A R A S T R O P H Y S I C S

N U C L E A R S C I E N C E L A B O R A T O R Y

CASPARAn underground Accelerator

Laboratory for Nuclear AstrophysicsManoel Couder

University of Notre Dame

I N S T I T U T E F O R S T R U C T U R E A N D N U C L E A R A S T R O P H Y S I C S

N U C L E A R S C I E N C E L A B O R A T O R Y

• Neutron sources for the s-process• CASPAR – Facility– Collaboration– Timeline

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I N S T I T U T E F O R S T R U C T U R E A N D N U C L E A R A S T R O P H Y S I C S

N U C L E A R S C I E N C E L A B O R A T O R Y s-process nucleosynthesisTwo components were identified and connected to stellar sites:

Main s-process ~90<A<210 Weak s-process A<~90TP-AGB stars 1-3 M⊙ 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

shell H-burning He-flash 0.9·108 K 3-3.5·108 K kT=8 keV kT=25 keV 107-108 cm-3 1010-1011 cm-3

13C(a,n)16O 22Ne(a,n)25Mg

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22Ne(a,n)25Mg Status of direct measurements

22Ne(α,n)25Mg

22Ne(α,n)25Mg

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HIgSLongland et al. 2009

26Mg(g, g)

ER = 11153.5(1) keV, Jπ = 1+ cannot contribute to the n-channel

26Mg(g,n)

1)2)3)

4)

5)

I N S T I T U T E F O R S T R U C T U R E A N D N U C L E A R A S T R O P H Y S I C S

N U C L E A R S C I E N C E L A B O R A T O R Y

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(a,a’) and (6Li,d) at RCNP Osaka22Ne(6Li,d) 26Mg(α,α’)

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N U C L E A R S C I E N C E L A B O R A T O R Y

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Status

13C(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, 025803 (2008)

Contribution from below thresholdat -3 keV has been evaluated withTrojan Horse Method.M. La Cognata et al.

I N S T I T U T E F O R S T R U C T U R E A N D N U C L E A R A S T R O P H Y S I C S

N U C L E A R S C I E N C E L A B O R A T O R YCASPAR

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Compact Accelerator System to Perform Astrophysics Research

At the Sanford Underground Research Facility (USA/SD)

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N U C L E A R S C I E N C E L A B O R A T O R YCASPAR

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Proton and Helium beam from a 200 kV to 1MV electrostatic acceleratorBombard an extended 22Ne gas target surroundedby 3He neutron detector

Complementary to LUNAresearch programDifferent energy rangeHelium beam allowed

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N U C L E A R S C I E N C E L A B O R A T O R Y

CASPAR10-3 to 10-4 neutron background of surface

S. Falahat et al., NIMA 700 (2013) 53

Low internal background 3He tube

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CASPARCollaboration between:University of Notre DameSouth Dakota School of Mines and TechnologyColorado School of Mines

Aggressive time line:Installation completed by mid-2015Will be operational before any newunderground accelerator program inthe world

JN 1MV accelerator (H and He beams)Refurbishment and control systemNeutron detectorTechnical support

Gas target for isotopically enriched gas

Local supportIn charge of operation

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Construct the laboratoryPartially fund theinstallation of CASPAR

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N U C L E A R S C I E N C E L A B O R A T O R Y

CASPAR Science goals

Neutron Sources and Neutron Poisons13C(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

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Other science goals• Other nuclear astrophysics questions• Reaction of interest for fusion energy and plasma physics

I N S T I T U T E F O R S T R U C T U R E A N D N U C L E A R A S T R O P H Y S I C S

N U C L E A R S C I E N C E L A B O R A T O R Y

• CASPAR– SDSM&T: D. Wells + ???– CSM: U. Greife– UND: H.-S. Jung , D. Robertson, K. Setoodehnia, M. Wiescher

– Friends @ UNC A. Champagne

Collaborations

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