A5046026390- Nuclear physics research studies
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- High-Energy Particle Collisions Research
- Advanced Chemical Physics Studies
- Radiation Therapy and Dosimetry
- Advanced NMR Techniques and Applications
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- X-ray Spectroscopy and Fluorescence Analysis
- Scientific Research and Discoveries
- Quantum, superfluid, helium dynamics
- Rare-earth and actinide compounds
- Magnetic confinement fusion research
- Atomic and Molecular Physics
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- Inorganic Fluorides and Related Compounds
- Astrophysics and Cosmic Phenomena
- Astronomical and nuclear sciences
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
Kent State University
1995-2023
Thomas Jefferson National Accelerator Facility
2017
Argonne National Laboratory
2017
Massachusetts Institute of Technology
1993-1994
Moscow Engineering Physics Institute
1994
Lawrence Berkeley National Laboratory
1994
TRIUMF
1993
The University of Melbourne
1985
U.S. National Science Foundation
1979-1983
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...
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 sqrt(s_NN)=130 GeV using STAR TPC RHIC. The signal, v_2, 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 than lower collision energies. Pseudorapidity momentum...
We report new measurements of the ratio electric form factor to magnetic neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties 7.6% 8.4% two higher points, which points have never been achieved in polarization measurements.
The H2(e,e’n)1H quasielastic cross section was measured at Q2 values of 0.109, 0.176, and 0.255 (GeV/c)2. neutron detection efficiency determined by the associated particle technique with H2(γ,pn) reaction for each three kinetic energies. These H2(e,e’n) measurements coincidence sections are first low Q2. sensitive primarily to magnetic form factor GMn these kinematics. extracted have smaller uncertainties than previous data consistent dipole parametrization two higher momentum transfers;...
We report values for the neutron electric to magnetic form factor ratio, ${G}_{\mathit{En}}/{G}_{\mathit{Mn}}$, deduced from measurements of neutron's recoil polarization in quasielastic $^{2}\mathrm{H}$$(\stackrel{\ensuremath{\rightarrow}}{e},{e}^{'}\stackrel{\ensuremath{\rightarrow}}{n})$$^{1}\mathrm{H}$ reaction, at three ${Q}^{2}$ 0.45, 1.13, and 1.45 (GeV/c)${}^{2}$. The data ${Q}^{2}=1.13$ (GeV/c)${}^{2}$ are first direct experimental ${G}_{\mathit{En}}$ employing degrees freedom...
Excitation-energy distributions of transition strength to ${1}^{+}$ states excited via the (p,n) reaction at 134.4 MeV on targets $^{76}\mathrm{Ge}$, $^{82}\mathrm{Se}$, $^{128}\mathrm{Te}$, and $^{130}\mathrm{Te}$ were measured for excitation energies up 25 MeV. Structures observed in neutron spectra with forward-peaked (\ensuremath{\Delta}L=0) angular identified as states, except isobaric analog transitions. The total these reactions was extracted by normalizing intensity peaks Fermi...
Gamow-Teller transition probabilities are extracted for eight nuclei with masses between $A=13 \mathrm{and} 39$ from medium-energy ($p, n$) reactions via the distorted-wave impulse approximation, and compared experimental $\ensuremath{\beta}$-decay free-nucleon probabilities. These comparisons indicate strongly that renormalization of operator needed on finite is different $\ensuremath{\beta}$ decay.
Gamow-Teller (GT) strength distributions were studied in the (p,n) reaction at 136 MeV on self-conjugate s-d shell nuclei $^{20}\mathrm{Ne}$,${\mathrm{}}^{24}$Mg, and $^{28}\mathrm{Si}$. The measurements performed two separate experiments with beam-swinger neutron time-of-flight facility Indiana University Cyclotron Facility. flight paths 91 131 m, respectively, for experiments. neutrons detected large-volume plastic-scintillation detectors. overall time resolutions about 825 ps; this...
The reaction plane of high-multiplicity Au-Au collisions at 650, 400, 250, 150, and 75 MeV/nucleon was determined by measuring the transverse velocity charged fragments. Measurements collective flow fragments reveal that onset in occurs a finite beam energy below 60 MeV/nucleon.
We measured neutron angular and energy distributions from 710-MeV alphas stopping in targets of water, carbon, steel, lead for energies 3 MeV to above 300 MeV. also spectra 640-MeV lead. These are similar the but reduced magnitude by about 20 percent. The forward peaked have a broad bump at 120 0- 6-degree spectra. integrated yields 10 0.5 per incident alpha, independent target. water target consistent with calculations an intranuclear cascade model angles, larger than backward...
The $^{54}\mathrm{Fe}$(p,n${)}^{54}$Co reaction was studied at 135 MeV by the time-of-flight technique. Neutrons were detected with an energy resolution of 245 keV in large-volume, mean-timed counters a flight path 125 m. forward-angle spectra are dominated excitation ${1}^{+}$ states characteristic \ensuremath{\Delta}l=0 angular distributions peaked 0\ifmmode^\circ\else\textdegree\fi{}. strengths excitations interpreted as being equivalent to Gamow-Teller (GT) excited beta decay. This...
Isovector stretched-state excitations were studied in the (p,n) reaction at 136 MeV on self-conjugate s-d shell nuclei $^{20}\mathrm{Ne}$, $^{24}\mathrm{Mg}$, $^{28}\mathrm{Si}$, and $^{32}\mathrm{S}$. The measurements performed three separate experiments using beam-swinger neutron time-of-flight facility Indiana University Cyclotron Facility. Neutrons detected large-volume plastic scintillation detectors located detector stations 0\ifmmode^\circ\else\textdegree\fi{},...
The excitation-energy distribution of transition strength to ${1}^{+}$ states excited via the $^{26}\mathrm{Mg}$(p,n${)}^{26}$Al reaction at 134.4 MeV was measured for excitation energies up 25 MeV. structures observed in neutron spectra with \ensuremath{\Delta}L=0 angular distributions were identified as states, except isobaric analog transition. total this extracted by normalizing intensity four lowest analogous beta decays these states. A detailed comparison experimental results known...
We measured inclusive double-differential cross sections at angles of 30, 45, 60, and 90 deg for the production neutrons above about 12 MeV from 337 MeV/nucleon neon ions bombarding targets C, Al, Cu, U. Three different energy regions can be distinguished in neutron spectra: (1) a low-energy "evaporation" region, (2) high-energy exponential tail reflecting internal momentum distribution nucleons, (3) an intermediate region quasifree preequilibrium processes. The intermediate-energy becomes...
The $^{40}\mathrm{Ca}$(p,n${)}^{40}$Sc reaction was studied at 134 MeV. Neutron energy spectra were measured by the time-of-flight technique with resolutions of 220 keV angles from 0\ifmmode^\circ\else\textdegree\fi{} to 41\ifmmode^\circ\else\textdegree\fi{} and 415 out 62\ifmmode^\circ\else\textdegree\fi{}. ${2}^{\mathrm{\ensuremath{-}}}$,${3}^{\mathrm{\ensuremath{-}}}$,${4}^{\mathrm{\ensuremath{-}}}$,${5}^{\mathrm{\ensuremath{-}}}$ band states based on...
Background: The strength of electron capture for medium mass nuclei has a significant effect on the evolution supernovae. There is insufficient knowledge these strengths and very little data important radioactive nuclei. Purpose: Determine whether it feasible to obtain EC from studies ${T}_{o}+1$ excitations in ($p$, $n$) reactions, this might yield information Methods: Cross sections $^{58,60,62,64}\mathrm{Ni}$($p$, $n$)$^{58,60,62,64}\mathrm{Cu}$ reactions were measured over angular range...
The wide-angle spectra of the 134-MeV ($p$, $n$) reaction on $^{48}\mathrm{Ca}$, $^{54}\mathrm{Fe}$, $^{88}\mathrm{Sr}$, and $^{208}\mathrm{Pb}$ are each dominated by excitation a single state at low energy. These excitations correspond to $``0\ensuremath{\hbar}\ensuremath{\omega}"$ stretched states seen be fragmented much less than $``1\ensuremath{\hbar}\ensuremath{\omega}"$ in medium- heavy-mass nuclei. normalization factors required for comparison with distorted-wave impulse-approximation...
Inclusive neutron spectra were measured at 0\ifmmode^\circ\else\textdegree\fi{}, 4\ifmmode^\circ\else\textdegree\fi{}, 8\ifmmode^\circ\else\textdegree\fi{}, 15\ifmmode^\circ\else\textdegree\fi{}, 30\ifmmode^\circ\else\textdegree\fi{}, and 42\ifmmode^\circ\else\textdegree\fi{} from Nb-Nb Au-Au collisions 800 MeV/nucleon. A peak that originates evaporation the projectile appears in angles out to 8\ifmmode^\circ\else\textdegree\fi{}. The shapes magnitudes of are compared with those calculated...
Inclusive neutron spectra were measured at 0\ifmmode^\circ\else\textdegree\fi{}, 15\ifmmode^\circ\else\textdegree\fi{}, 30\ifmmode^\circ\else\textdegree\fi{}, 50\ifmmode^\circ\else\textdegree\fi{}, 70\ifmmode^\circ\else\textdegree\fi{}, 90\ifmmode^\circ\else\textdegree\fi{}, 120\ifmmode^\circ\else\textdegree\fi{}, and 160\ifmmode^\circ\else\textdegree\fi{} from Ne-Pb collisions 790 MeV/nucleon. A peak that originates evaporation the projectile appears in 0\ifmmode^\circ\else\textdegree\fi{}....
We measured the energy spectra and yields of neutrons above 1.2 MeV from nuclear capture negative pions slowing down stopping in C, N, O, Al, Cu, Ta, Pb targets. Each neutron spectrum was decomposed into an evaporation portion a direct portion. The number per stopped pion is substantially constant for all targets with mean value 1.74\ifmmode\pm\else\textpm\fi{}0.28, whereas yield increases by order magnitude about 0.7 carbon to 7 lead. total kinetic carried away also...