Transcript Nuclear Astrophysics Carl R. Brune Ohio University, Athens Ohio ARUNA Workshop, Notre Dame, IN June 12-13, 2014

Nuclear Astrophysics
Carl R. Brune
Ohio University, Athens Ohio
ARUNA Workshop, Notre Dame, IN
June 12-13, 2014
Beam Swinger Neutron Time-of-Flight Facility
at Ohio University
Edwards Accelerator Laboratory
Target
chamber
4.5-MV
T-shaped tandem
Swinger Magnet
(-4°  qlab  158°)
Cs Sputter Source
30-meter TOF
Tunnel
Duoplasmatron He Source
Neutron Time-of-Flight Technique
24Mg
+ 3He  26Si(*) + n
neutron flight path (≤30m)
Beam (3He)
neutron
detector
Target (24Mg)
• time of flight  neutron energy
• kinematics  Ex in 26Si
• Dt ≈ 2 ns
• long flight path, low En desirable
• NE-213 scintillator  neutron / gamma discrimination
Excellent energy resolution achievable (10 keV) !
Neutron Energy Spectra
(Y. Parpottas)
full spectra
24Mg(3He,n)26Si(*)
Key Result
Mirror nucleus leads us to expect
3+ and 0+ in this region.
16O(3He,n)18Ne
(Y. Parpottas)
G(4.527) = 17(4) keV
Neutron Energy (MeV)
Additional Considerations
• Charged-Particle or Gamma Coincidence
(Sergio Almarez-Calderon et al.)
• Future need: more intense 3He/α sources
• Specific cases:
- 19Ne via 19F(p,n) (for 18F+p)
- 42Ti via 40Ca(3He,n) for 41Ti(p,γ)42Ti
Other Nuclear Astrophysics Projects:
• Sub-coulomb transfer reactions
• Statistical model studies