D. W. Stracener
A5083516196- Nuclear physics research studies
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- Nuclear reactor physics and engineering
- Atomic and Molecular Physics
- Quantum Chromodynamics and Particle Interactions
- Particle accelerators and beam dynamics
- Nuclear Materials and Properties
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Radioactive contamination and transfer
- Radiation Detection and Scintillator Technologies
- Radioactive Decay and Measurement Techniques
- Advanced NMR Techniques and Applications
- Radiopharmaceutical Chemistry and Applications
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Physics Studies
- Radioactive element chemistry and processing
- Radiation Effects in Electronics
- Astro and Planetary Science
- High-Energy Particle Collisions Research
- Laser-Matter Interactions and Applications
- Ion-surface interactions and analysis
- Laser Design and Applications
Oak Ridge National Laboratory
2015-2024
University of Warsaw
2021
State University of New York at Oswego
2009
University of Notre Dame
2009
Oregon State University
2009
University of Tennessee at Knoxville
2009
Oak Ridge Associated Universities
1997-2009
Oak Ridge Institute for Science and Education
1997
Martin Marietta Materials (United States)
1996
Michigan State University
1993
The B(E2;0(+)-->2+) values for the first 2+ excited states of neutron-rich 132,134,136Te have been measured using Coulomb excitation radioactive ion beams. B(E2) obtained 132,134Te are in excellent agreement with expectations based on systematics heavy stable Te isotopes, while that 136Te is unexpectedly small. These results discussed terms proton-neutron configuration mixing and shell-model calculations realistic effective interactions.
The best examples of halo nuclei, exotic systems with a diffuse nuclear cloud surrounding tightly bound core, are found in the light, neutron-rich region, where neutrons experience only weak binding and weak, or no, potential barrier. Modern direct-reaction measurement techniques provide powerful probes structure nuclei. Despite more than four decades these studies on benchmark one-neutron nucleus 11Be, spectroscopic factors for two states remain poorly constrained. In present work,...
Radioactive ion beams of ${}^{17}\mathrm{F}$ were used to study several resonance states in ${}^{18}\mathrm{Ne}$. Clear evidence for simultaneous two-proton emission from the 6.15 MeV state $({J}^{\ensuremath{\pi}}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1}^{\ensuremath{-}})$ ${}^{18}\mathrm{Ne}$ has been observed with reaction ${}^{17}\mathrm{F}{+}^{1}\mathrm{H}$. Because limited angular coverage, data did not differentiate between two possible mechanisms decay, diproton...
We report total absorption spectroscopy measurements of ^{92}Rb, ^{96gs}Y, and ^{142}Cs β decays, which are the most important contributors to high energy ν[over ¯]_{e} spectral shape in nuclear reactors. These three decays contribute 43% flux near 5.5 MeV emitted by This is particularly interesting due features recently observed several experiments including Daya Bay, Double Chooz, RENO Collaborations. Measurements were conducted at Oak Ridge National Laboratory means proton-induced fission...
High energy \ensuremath{\gamma} rays from the decay of giant resonance in hot ${}^{120}$Sn nuclei were measured excitation range 30--130 MeV. The excited populated by inelastic scattering \ensuremath{\alpha} particles at 40 and 50 MeV/nucleon. width was observed to increase monotonically with increasing energy, 5 MeV ground state $\ensuremath{\sim}12$ largest energy. Inelastic predominantly populates low angular momentum states, is thus attributed fluctuations nuclear shape induced temperature.
The β decays of neutron-rich nuclei near the doubly magic (78)Ni were studied at Holifield Radioactive Ion Beam Facility using an electromagnetic isobar separator. half-lives (82)Zn (228±10 ms), (83)Zn (117±20 and (85)Ga (93±7 ms) determined for first time. These found to be very different from predictions global model used in astrophysical simulations. A new calculation was developed density functional model, which properly reproduced experimental values. robustness region allowed us...
The excitation functions for quasielastic scattering of ^{22}Ne+^{248}Cm, ^{26}Mg+^{248}Cm, and ^{48}Ca+^{238}U are measured using a gas-filled recoil ion separator. barrier distributions extracted these systems compared with coupled-channel calculations. results indicate that the distribution is affected dominantly by deformation actinide target nuclei, but also vibrational or rotational excitations projectile as well neutron transfer processes before capture. From comparison between...
The quasielastic barrier distribution of 51V+248Cm was extracted by measuring the excitation function backscattering using a gas-filled recoil ion separator, GARIS-III. obtained is well explained coupled-channels calculation, indicating significant effect rotational deformed 248Cm. From measured average Coulomb height and deformation parameters 248Cm, side-collision energy leading to compact configuration colliding nuclei obtained. relation between side collision evaporation-residue cross...
Neutron emission probabilities and half-lives of 37 <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>β</a:mi></a:mrow></a:math>-delayed neutron emitters from <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mmultiscripts><c:mrow><c:mi>Ni</c:mi></c:mrow><c:mprescripts/><c:none/><c:mrow><c:mn>75</c:mn></c:mrow></c:mmultiscripts></c:mrow></c:math> to <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"...
The B(E2;0(+)(1)-->2(+)(1)) values for the radioactive neutron-rich germanium isotopes (78,80)Ge and closed neutron shell nucleus 82Ge were measured at HRIBF using Coulomb excitation in inverse kinematics. These data allow a study of systematic trend between subshell closures N=40 50. B(E2) behavior approaching N=50 is similar to observed heavier isotopic chains. A comparison experimental results with model calculation demonstrates persistence gap strong sensitivity effective interaction.
Evaporation residue and fission cross sections of radioactive $^{132}\mathrm{Sn}$ on $^{64}\mathrm{Ni}$ were measured near the Coulomb barrier. A large subbarrier fusion enhancement was observed. Coupled-channel calculations, including inelastic excitation projectile target, neutron transfer are in good agreement with function. When change nuclear size shift barrier height accounted for, there is no extra $^{132}\mathrm{Sn}$+$^{64}\mathrm{Ni}$ respect to stable Sn+$^{64}\mathrm{Ni}$....
Beta decay of 86Ga was studied by means β-neutron-γ spectroscopy. An isotopically pure ^{86}Ga beam produced at the Holifield Radioactive Ion Beam Facility using a resonance ionization laser ion source and high-resolution electromagnetic separation. The revealed half-life 43(-15)(+21) ms large β-delayed one-neutron two-neutron branching ratios P1n=60(10)% P2n=20(10)%. βγ populated 527 keV transition that is interpreted as deexcitation first 2+ state in N=54 isotone 86Ge suggests quick onset...
Theoretical models of β-delayed neutron emission are used as crucial inputs in r-process calculations. Benchmarking the predictions these is a challenge due to lack currently available experimental data. In this work probabilities 33 nuclides important mass regions south and south-west 132Sn presented, 16 for first time. The measurements were performed at RIKEN using Advanced Implantation Detector Array (AIDA) BRIKEN detector array. P1n values presented constrain theoretical region,...
Evaporation residue cross sections have been measured with neutron-rich radioactive 132Sn beams on 64Ni in the vicinity of Coulomb barrier. The average beam intensity was 2 x 10(4) particles per second and smallest section less than 5 mb. Large sub-barrier fusion enhancement observed. Coupled-channel calculations taking into account inelastic excitation significantly underpredict below presence several neutron transfer channels large positive Q values suggests that multinucleon may play an...
High energy \ensuremath{\gamma} rays from the decay of giant dipole resonance built on highly excited states in $^{164}\mathrm{Yb}$ at ${\mathit{E}}_{\mathrm{ex}}$=49 MeV formed two different reactions have been measured. While standard statistical model calculations can describe \ensuremath{\gamma}-ray spectrum $^{16}\mathrm{O}$ + $^{148}\mathrm{Sm}$ reaction they fail to reproduce spectra more symmetric $^{64}\mathrm{Ni}$ $^{100}\mathrm{Mo}$. Simple which include particle evaporation and...
The β-delayed neutron emission of ^{83,84}Ga isotopes was studied using the time-of-flight technique. measured energy spectra showed from states at excitation energies high above separation and previously not observed in β decay midmass nuclei. large strength deduced intense is a signature Gamow-Teller transformation. This observation interpreted as evidence for allowed to ^{78}Ni core-excited ^{83,84}Ge favored by shell effects. We developed model calculations proton fpg_{9/2} extended...
Decays of neutron-rich nuclei $^{82,83}\mathrm{Zn}$ and $^{82,83}\mathrm{Ga}$ produced in proton-induced fission $^{238}\mathrm{U}$ were studied at the Holifield Radioactive Ion Beam Facility using on-line mass separation $\ensuremath{\beta}\text{\ensuremath{-}}\ensuremath{\gamma}$ spectroscopy techniques. New $\ensuremath{\gamma}$-ray transitions identified level schemes, which include states high excitation energies range between 3--7 MeV constructed. These high-energy levels to be...
The $\ensuremath{\beta}$-delayed one- and two-neutron emission probabilities (${P}_{1n}$ ${P}_{2n}$) of 20 neutron-rich nuclei with $N\ensuremath{\ge}82$ have been measured at the RIBF facility RIKEN Nishina Center. ${P}_{1n}$ $^{130,131}\mathrm{Ag}$, $^{133,134}\mathrm{Cd}$, $^{135,136}\mathrm{In}$, $^{138,139}\mathrm{Sn}$ were determined for first time, stringent upper limits placed on ${P}_{2n}$ nearly all cases. ($\ensuremath{\beta}2n$) was unambiguously identified in $^{133}\mathrm{Cd}$...