CASPAR An underground Accelerator Laboratory for Nuclear Astrophysics
description
Transcript of CASPAR An underground Accelerator Laboratory for Nuclear Astrophysics
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
ARUNA 2014
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
ARUNA 2014
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
ARUNA 2014
22Ne(a,n)25Mg Status of direct measurements
22Ne(α,n)25Mg
22Ne(α,n)25Mg
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
ARUNA 2014
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
ARUNA 2014
(a,a’) and (6Li,d) at RCNP Osaka22Ne(6Li,d) 26Mg(α,α’)
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
ARUNA 2014
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
ARUNA 2014
Compact Accelerator System to Perform Astrophysics Research
At the Sanford Underground Research Facility (USA/SD)
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
ARUNA 2014
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
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
CASPAR10-3 to 10-4 neutron background of surface
S. Falahat et al., NIMA 700 (2013) 53
Low internal background 3He tube
ARUNA 2014
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
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
ARUNA 2014
Construct the laboratoryPartially fund theinstallation of CASPAR
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 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
ARUNA 2014
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
ARUNA 2014