Heavy Ion Discussion Group
Conference Room R-150, Building 203, Argonne National Laboratory
Fridays at 3:30 PM
|24 Aug 2015||Special Day: Monday
Sean Kuvin, Florida State University,
"Measurement of the 17F (d, n)18Ne reaction using RESONEUT"
The 17F(p, γ)18Ne reaction of astrophysical importance has been studied using the
surrogate reaction 17F(d, n)18Ne in inverse kinematics. The usefulness of this type of
approach has been demonstrated in previous experiments at the RESOLUT facility.
In this work we have developed a compact neutron detector array, RESONEUT, which
is specialized for (d, n) reactions in inverse kinematics. The threshold and efficiency
properties of the neutron detectors were characterized using the 12C(d, n)13N reaction.
Spectroscopy of the 18Ne nucleus was accomplished using two methods. The first was by
neutron time of flight spectroscopy and the second was by kinematic reconstruction of the
unbound compound nucleus by detecting the emitted proton and heavy ion. We compared
our results with those obtained from 17F+p elastic scattering measurements and from the
direct 17F(p, γ) measurement conducted at Oak Ridge[2,3]. Our results provide additional
confirmation that the state at ~600 keV is the 3+ state. No other resonances directly
above the proton threshold were detected. However, using NaI(T1) detectors detecting
gammas in coincidence with the neutrons in RESONEUT, we have placed upper limits on
the possibility of having a low-lying proton resonance with a significant Γγ > Γp branching
|27 Aug 2015||Special Day: Thursday
Ran Hong, University of Washington,
High-Precision Measurement of the β-ν Correlation in the 6He Decay
High-precision measurements of β-decays are sensitive probes of new physics beyond the Standard Model (SM). Particularly, the β-ν correlation of Gamow-Teller decays is sensitive to the exotic tensor type weak current which is predicted by the leptoquark model and some super symmetric models. A new experiment that measures the β-ν correlation coefficient αβν of the 6He decay is being developed at the Center of Experimental Nuclear Physics and Astrophysics (CENPA), University of Washington. In this experiment, the 6He atoms are laser-trapped while both the
β-particle and the recoil ion are detected.
The αβν is extracted by fitting the time-of-flight (TOF) spectrum of the recoil ions. The ultimate goal of this experiment is a 0.1% determination of αβν and the short-term goal is to determine αβν at or lower than 1% and pave the way to the 0.1% level measurement.
|31 Aug 2015||Special Day: Monday
Kenneth Whitmore, Michigan State University,
New Experimental Probes of the Halo Nucleus 19C
Halo nuclei occur at the limits of stability, where a low binding energy allows valence nucleons to tunnel beyond the nuclear core to form a diffuse nuclear cloud. Several experimental probes have been used to identify and characterize halo nuclei, including interaction cross section measurements, momentum distributions following knockout reactions, and Coulomb dissociation reactions. In particular, an enhanced electric dipole (E1) response at low energy has become a unique signature of halo nuclei. Despite numerous investigations into the E1 response, there is very little information on the magnetic dipole (M1) response of halo nuclei.
|3 Sep 2015||Special Day: Thursday
Michael Jones, Michigan State University,
|11 Sep 2015||Calem Hoffman, Physics Division, Argonne National Laboratory
|17 Sep 2015||Special Day: Thursday
Kalle Auranen, University of Jyvaskyla,
|25 Sep 2015||Torben Lauritsen, Physics Division, Argonne National Laboratory
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