117 research outputs found
TriSol: a major upgrade of the TwinSol RNB facility
We report here on the recent upgrade of the TwinSol radioactive nuclear beam
(RNB) facility at the University of Notre Dame. The new TriSol system includes
a magnetic dipole to provide a second beamline and a third solenoid which acts
to reduce the size of the radioactive beam on target.Comment: submitted to Nuclear Instruments and Methods
Unbound states of 32Cl and the 31S(p,\gamma)32Cl reaction rate
The 31S(p,\gamma)32Cl reaction is expected to provide the dominant break-out
path from the SiP cycle in novae and is important for understanding enrichments
of sulfur observed in some nova ejecta. We studied the 32S(3He,t)32Cl
charge-exchange reaction to determine properties of proton-unbound levels in
32Cl that have previously contributed significant uncertainties to the
31S(p,\gamma)32Cl reaction rate. Measured triton magnetic rigidities were used
to determine excitation energies in 32Cl. Proton-branching ratios were obtained
by detecting decay protons from unbound 32Cl states in coincidence with
tritons. An improved 31S(p,\gamma)32Cl reaction rate was calculated including
robust statistical and systematic uncertainties
Mg(, )Na reaction study for spectroscopy of Na
The Mg(, )Na reaction was measured at the Holifield
Radioactive Ion Beam Facility at Oak Ridge National Laboratory in order to
better constrain spins and parities of energy levels in Na for the
astrophysically important F()Ne reaction rate
calculation. 31 MeV proton beams from the 25-MV tandem accelerator and enriched
Mg solid targets were used. Recoiling He particles from the
Mg(, )Na reaction were detected by a highly segmented
silicon detector array which measured the yields of He particles over a
range of angles simultaneously. A new level at 6661 5 keV was observed in
the present work. The extracted angular distributions for the first four levels
of Na and Distorted Wave Born Approximation (DWBA) calculations were
compared to verify and extract angular momentum transfer.Comment: 11 pages, 6 figures, proceedings of the 18th International Conference
on Accelerators and Beam Utilization (ICABU2014
Experimental study of the nature of the 1− and 2− excited state
The nature of the 1− and 2− excited states in 10Be is studied using the 11Be(p, d) transfer reaction in
inverse kinematics at 10A MeV at TRIUMF ISAC-II, in particular to assess whether either of them can be
considered as an excited halo state. The angular distributions for both states are extracted using deuteron-γ
coincidences and analyzed using a transfer model taking into account one-step and two-step processes. A good
fit of the angular distributions is obtained considering only the one-step process, whereby an inner p3/2 neutron
of 11Be is removed, leaving the halo neutron intact. Higher-order processes however cannot be rejected. The
small spectroscopic factors extracted suggest that the structure of both states is not uniquely halo-like, but
rather display a more complex configuration mixing cluster and halo structures. Further insights are limited, as
this experiment specifically probed the halo-like (but not cluster-like) 11Be(1/2+) ⊗ (ν p3/2 )
−1 configuration in
both states.U.S. Department of Energy (DOE): DE-FG03-93ER40789 (Colorado School of Mines), DE-FG02-96ER40978 (Louisiana State), DE-SC0021422 (Michigan State), DE-AC05-00OR22725 (Oak Ridge National Laboratory)The National Nuclear Security Administration a través de los acuerdos de cooperación del DOE de EE. UU.(NNSA) DE-FG52-08NA28552The National Science Foundation PHY-1811815 (Michigan State)Ministerio español de Ciencia e Innovación y fondos FEDER. RTI2018-098117-B-C21 y PGC2018-096994-BC21Agencia Española de Investigación (AEI). PID2019-104714GB-C2
New Features in the Computational Infrastructure for Nuclear Astrophysics
A Computational Infrastructure for Nuclear Astrophysics has been developed to streamline the inclusion of the latest nuclear physics data in astrophysics simulations. The infrastructure consists of a platform-independent suite of computer codes that are freely available online at http://nucastrodata.org. The newest features of, and future plans for, this software suite are given. © Copyright owned by the author(s)
Reactions of a Be-10 beam on proton and deuteron targets
The extraction of detailed nuclear structure information from transfer
reactions requires reliable, well-normalized data as well as optical potentials
and a theoretical framework demonstrated to work well in the relevant mass and
beam energy ranges. It is rare that the theoretical ingredients can be tested
well for exotic nuclei owing to the paucity of data. The halo nucleus Be-11 has
been examined through the 10Be(d,p) reaction in inverse kinematics at
equivalent deuteron energies of 12,15,18, and 21.4 MeV. Elastic scattering of
Be-10 on protons was used to select optical potentials for the analysis of the
transfer data. Additionally, data from the elastic and inelastic scattering of
Be-10 on deuterons was used to fit optical potentials at the four measured
energies. Transfers to the two bound states and the first resonance in Be-11
were analyzed using the Finite Range ADiabatic Wave Approximation (FR-ADWA).
Consistent values of the spectroscopic factor of both the ground and first
excited states were extracted from the four measurements, with average values
of 0.71(5) and 0.62(4) respectively. The calculations for transfer to the first
resonance were found to be sensitive to the size of the energy bin used and
therefore could not be used to extract a spectroscopic factor.Comment: 16 Pages, 10 figure
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