A5087857274- Nuclear physics research studies
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Nuclear reactor physics and engineering
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Advanced Chemical Physics Studies
- Particle physics theoretical and experimental studies
- X-ray Spectroscopy and Fluorescence Analysis
- Superconducting Materials and Applications
- High-Energy Particle Collisions Research
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Nuclear Materials and Properties
- Particle Detector Development and Performance
- Scientific Research and Discoveries
- Dark Matter and Cosmic Phenomena
- Electron and X-Ray Spectroscopy Techniques
- Quantum Dots Synthesis And Properties
- Radiation Therapy and Dosimetry
- Astro and Planetary Science
- Computational Physics and Python Applications
Hope College
2015-2024
Instituto Nacional de Investigaciones Nucleares
2017
National Superconducting Cyclotron Laboratory
2006-2010
Michigan State University
2006-2010
Stony Brook University
1984-2008
State University of New York
1986-2008
Holland Hospital
2007
Carnegie Mellon University
1987-2003
Lawrence Berkeley National Laboratory
1991-1996
University of Notre Dame
1980-1986
Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic charged particles at midrapidity in Au+Au square root(S)NN = 130 GeV using STAR Time Projection Chamber Relativistic Heavy Ion Collider. The signal, v2, averaged over transverse momentum, reaches values about 6% for relatively peripheral and decreases more central collisions. This can be interpreted as observation higher degree thermalization...
Elastic scattering of $^{8}\mathrm{B}$, $^{7}\mathrm{Be}$, and $^{6}\mathrm{Li}$ on a $^{58}\mathrm{Ni}$ target has been measured at energies near the Coulomb barrier. Optical-model fits were made to experimental angular distributions, total reaction cross sections deduced. A comparison with other systems provides striking evidence for proton-halo effects $^{8}\mathrm{B}$ reactions. As opposed situation neutron-halo nucleus $^{6}\mathrm{He}$, which particle transfer dominates, ``extra''...
The neutron unbound ground state of (25)O (Z=8, N=17) was observed for the first time in a proton knockout reaction from (26)F beam. A single resonance found invariant mass spectrum corresponding to decay energy 770_+20(-10) keV with total width 172(30) keV. N=16 shell gap established be 4.86(13) MeV by difference between nu1s(1/2) and nu0d(3/2) orbitals. separation energies agree calculations universal sd model interaction. This interaction incorrectly predicts an (26)O that is bound...
We report on the first observation of dineutron emission in decay 16Be. A single-proton knockout reaction from a 53 MeV/u 17B beam was used to populate ground state 16Be is bound with respect one neutron and unbound two-neutron emission. The character evidenced by small angle between two neutrons. separation energy measured be 1.35(10) MeV, good agreement shell model calculations, using standard interactions for this mass region.
Evidence for the ground state of neutron-unbound nucleus 26O was observed first time in single proton-knockout reaction from a 82 MeV/u 27F beam. Neutrons were measured coincidence with 24O fragments. determined to be unbound by 150+50-150 keV observation low-energy neutrons. This result agrees recent shell model calculations based on microscopic two- and three-nucleon forces.
Reaction products from the interaction of ${}^{6}\mathrm{He}$ with ${}^{209}\mathrm{Bi}$ have been measured at energies near Coulomb barrier. A ${}^{4}\mathrm{He}$ group remarkable intensity, which dominates total reaction cross section, has observed. The angular distribution suggests that it results primarily a direct nuclear process. It is likely this transfer and/or breakup channel doorway state accounts for previously observed large sub-barrier fusion enhancement in system.
The interaction of ${}^{6}\mathrm{He}$ with ${}^{209}\mathrm{Bi}$ has been studied over a range energies well below the nominal Coulomb barrier. A ${}^{4}\mathrm{He}$ group remarkable intensity, first observed in previous experiment at near-barrier energies, continues to dominate reaction sub-barrier regime. total cross section nearly 200 mb was measured for this 6 MeV This very large value is shown be consistent deduced from simultaneously-measured elastic scattering angular distribution.
Fusion cross sections were measured for the exotic proton-halo nucleus ⁸B incident on a ⁵⁸Ni target at several energies near Coulomb barrier. This is first experiment to report fusion of nucleus. The resulting excitation function shows striking enhancement with respect expectations normal projectiles. Evidence presented that sum and breakup yields saturates total reaction section.
This repeated measures psychophysiology experiment studied three responses to a past interpersonal offense (38 females and 33 males). We compared rumination with two reappraisal strategies. Compassion-focused emphasized the offender's humanity, interpreted transgression as evidence of need for positive transformation. Benefit-focused insights gained or strengths shown in facing offense. Supporting manipulations, compassion-focused stimulated most empathy forgiveness, whereas benefit-focused...
The cross section for \ensuremath{\alpha}-particle emission in the $^{6}\mathrm{He}+^{209}\mathrm{Bi}$ reaction at energies near Coulomb barrier is remarkably large. Possible reactions that may produce observed \ensuremath{\alpha} particles include two-neutron transfer, one-neutron and direct projectile breakup. Each of these mechanisms results a distinctive angular correlation between particle outgoing neutron(s). A neutron-\ensuremath{\alpha}-particle coincidence experiment was performed...
We have observed a resonance in neutron-fragment coincidence measurements that is presumably the first excited state of $^{23}\mathrm{O}$ at 2.8(1) MeV excitation energy which decays into ground $^{22}\mathrm{O}$. This interpretation consistent with theory. The reaction mechanism supports assignment as $5/{2}^{+}$ hole state. and recently $3/{2}^{+}$ particle advance understanding $^{23}\mathrm{O}$.
This within subjects experiment (28 females, 26 males) examined three responses to a past interpersonal offender. We contrasted offense-focused rumination with two subsequent, counterbalanced coping strategies: compassionate reappraisal and emotion suppression. Compassionate emphasized the offender's human qualities need for positive change. Emotion suppression inhibited experience expression of negative offense-related emotions. Offense was associated emotion, faster heartbeats (i.e.,...
New astronomical observations point to a nucleosynthesis picture that goes beyond what was accepted until recently.The intermediate "i" process proposed as plausible scenario explain some of the unusual abundance patterns observed in metal-poor stars.The most important nuclear physics properties entering i-process calculations are neutron-capture cross sections and they almost exclusively not known experimentally.Here we provide first experimental constraints on 139 Baðn; γÞ 140 Ba reaction...
A neutron-\ensuremath{\alpha}-particle coincidence experiment was performed to study breakup of $^{6}\mathrm{He}$ on a $^{209}\mathrm{Bi}$ target at an incident energy 22.5 MeV. Direct breakup, as well through the ${2}^{+}$ excited state and also $^{5}\mathrm{He}$$+n$ channel, could be distinguished. total cross section $205\ifmmode\pm\else\textpm\fi{}65$ mb measured. The data compare with coupled-channels calculation that assumes 50% reduction in B(E1) computed from pure...
A new resonance having a relative decay energy of $~0.6$ MeV has been observed above the two-neutron separation in $^{24}\mathrm{O}$ at an excitation $~7.5$ MeV. The level was found to directly feed first excited state $^{23}\mathrm{O}$, $E=0.045(2)$-MeV resonance, through measurement neutron-neutron correlations. Energy comparisons with $^{23}\mathrm{O}$ suggest that this is dominated by unpaired neutron $\ensuremath{\nu}0{d}_{3/2}$ single-particle orbital coupled single hole...
The ground state of neutron-rich unbound ${}^{13}$Li was observed for the first time in a one-proton removal reaction from ${}^{14}$Be at beam energy 53.6 MeV/u. reconstructed ${}^{11}$Li and two neutrons giving resonance 120${}_{\ensuremath{-}80}^{+60}$ keV. All events involving single- double-neutron interactions Modular Neutron Array (MoNA) were analyzed, simulated, fitted self-consistently. three-body (${}^{11}\text{Li}+n+n$) correlations within Jacobi coordinates showed strong dineutron...
The Modular Neutron Array (MoNA) collaboration was initiated in 2000 at the National Superconducting Cyclotron Laboratory (NSCL) Michigan State University (MSU). Since then, studied properties of nuclides and beyond neutron dripline discovering seven new isotopes between lithium to fluorine. included liberal arts colleges, regional comprehensive universities, major research universities with focus giving undergraduate students meaningful experiences. Over last 25 years, combined efforts...
Charged-particle emission has been studied in ten heavy-ion reactions spanning composite systems of 16\ensuremath{\le}Z\ensuremath{\le}64. By means reversed kinematics, high-quality energy spectra were obtained for proton and alpha evaporation from compound nuclei with temperatures \ensuremath{\sim}1.5--3.5 MeV spins up to \ensuremath{\sim}70\ensuremath{\Elzxh}. In some cases, deuteron triton recorded as well. Statistical model calculations spherical require systematically low barriers...