A5020683066- Nuclear physics research studies
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- Advanced NMR Techniques and Applications
- Nuclear reactor physics and engineering
- Radioactive Decay and Measurement Techniques
- Rare-earth and actinide compounds
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Advanced Chemical Physics Studies
- Superconducting Materials and Applications
- High-pressure geophysics and materials
- X-ray Spectroscopy and Fluorescence Analysis
- Astro and Planetary Science
- Neutrino Physics Research
- Quantum, superfluid, helium dynamics
- High-Energy Particle Collisions Research
- Inorganic Fluorides and Related Compounds
- Solid-state spectroscopy and crystallography
- Mass Spectrometry Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Radiopharmaceutical Chemistry and Applications
Jimma University
2024
Vanderbilt University
2012-2021
Kurchatov Institute
2016
Tsinghua University
2009
Lawrence Berkeley National Laboratory
2009
Joint Institute for Nuclear Research
2009
Idaho National Laboratory
1996-2009
Slovak Academy of Sciences
2009
Oak Ridge Associated Universities
2009
Lawrence Livermore National Laboratory
2009
We report evidence for an excited ${K}^{\ensuremath{\pi}}={0}^{+}$ rotational band in $^{72}\mathrm{Se}$ and its mixing with vibrational states. The mean life of the 937-keV ${0}^{+}$\ensuremath{'} state was measured to be 22.8\ifmmode\pm\else\textpm\fi{}1.4 nsec, yielding $B(E2)=36\ifmmode\pm\else\textpm\fi{}7$ single-particle units 75-keV \ensuremath{\rightarrow} ${2}^{+}$ transition. From in-beam, $\ensuremath{\gamma}$-ray spectroscopy following reaction $^{58}\mathrm{Ni}(^{16}\mathrm{O},...
The levels in $^{74,76}\mathrm{Kr}$ were studied with in-beam $\ensuremath{\gamma}$-spectroscopy techniques and the ${\ensuremath{\beta}}^{+}$ decay of $^{76}\mathrm{Rb}$. energies ${2}_{1}^{+}$ states deviate from smooth behavior compared higher spin levels. yrast cascade $B(E2)$'s are highly collective. ground have unusually large deformation. origin this deformation shape coexistence region is described terms protons driving
New isotopes $^{186,188}\mathrm{Tl}$ (${{T}_{\frac{1}{2}}}^{186}={4.5}_{\ensuremath{-}1.5}^{+1.0} \mathrm{and} 28\ifmmode\pm\else\textpm\fi{}2$ sec and ${{T}_{\frac{1}{2}}}^{188}=71\ifmmode\pm\else\textpm\fi{}1$ sec, respectively) have been identified. Conversion-electron, $\ensuremath{\gamma}$, $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$, $e\ensuremath{-}\ensuremath{\gamma}$ studies helped establish in $^{186,188}\mathrm{Hg}$ two bands, one built on a slightly deformed ground...
The new isotope $^{184}\mathrm{Tl}$ has been identified with ${T}_{\frac{1}{2}}=11\ifmmode\pm\else\textpm\fi{}1$ sec and the levels in $^{184}\mathrm{Hg}$ investigated from its decay. ${0}^{+}$ band head of a deformed was found to drop 375 keV agreement theoretical predictions. mean life 375-keV level measured be 0.9 \ifmmode\pm\else\textpm\fi{} 0.3 nsec which is factor 10 faster than theoretically predicted for shape-isomeric $E2$ transition.
The emission of ${}^{10}\mathrm{Be}$ in ternary cold neutronless spontaneous fission ${}^{252}\mathrm{Cf}$ is observed with the Gammasphere consisting 72 detectors. $\ensuremath{\gamma}$ ray corresponding to decay first ${2}^{+}$ state coincidence rays partners ${}^{96}\mathrm{Sr}$ and ${}^{146}\mathrm{Ba}$. yield excited ${}^{96}\mathrm{Sr}{\ensuremath{-}}^{146}\mathrm{Ba}$ split order $4.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ per 100 events.
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...
High resolution $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ and $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidences in the spontaneous fission of $^{252}\mathrm{Cf}$ were measured. Relative yields neutron multiplicities from zero up to 10 extracted directly for first time Zr-Ce Mo-Ba correlated fragment pairs. The 0, 8, new emission are significantly larger than those reported previously total fission. Our results demonstrate that...
Several $\ensuremath{\gamma}$ transitions in ${}^{101--103}\mathrm{Nb},{ }^{98,100}\mathrm{Y},{ }^{146}\mathrm{La},$ and ${}^{149}\mathrm{Pr}$ are identified from spontaneous fission studies employing a ${}^{252}\mathrm{Cf}$ source the Gammasphere detector array. In particular, pairing-free bands ${}^{100}\mathrm{Y}$ ${}^{102}\mathrm{Nb}$ extended, two rather highly deformed negative-parity feeding 4.3-s $\ensuremath{\beta}$-decaying isomer of identified, their possible bandhead...
Several γ transitions in 105−109Tc nuclei were identified for the first time from spontaneous fission studies with a 252Cf source and Gammasphere. New level schemes are proposed related to underlying nuclear structure. Positive parity bands large signature splitting observed 105,107,109Tc evidently derived g9/2 orbitals similar analogous 103Rh,103Ag, 99Y. have also been 139−143Cs used construct these isotopes. Correlated-pair yields extracted data show an appreciable field zero neutron...
Level schemes of $^{111}\mathrm{Rh}$ and $^{113}\mathrm{Rh}$ are proposed from the analysis $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ coincidence data a $^{252}\mathrm{Cf}$ spontaneous fission source with Gammasphere. These have highest excitation energies spins yet established in these nuclei, as well weakly populated bands not reported earlier fission-$\ensuremath{\gamma}$ work. From data, information on shapes is inferred. By...
The vibrational states of $^{154,156,158,160}\mathrm{Gd}$ and $^{176,178,180}\mathrm{Hf}$ have been studied via Coulomb excitation. Thin high-purity targets were prepared in an isotope separator. excitation these nuclei was by the scattering 11-17 MeV $\ensuremath{\alpha}$ particles. particles detected Enge split-pole spectrograph. reduced transition probabilities $B(E\ensuremath{\lambda}; {0}_{\mathrm{g}.\mathrm{s}.}^{+}\ensuremath{\rightarrow}{I}^{\ensuremath{\pi}}K)$, obtained for...
We report the results of a β-decay study fission products ^{86}Br, ^{89}Kr, ^{89}Rb, ^{90gs}Rb, ^{90m}Rb, ^{90}Kr, ^{92}Rb, ^{139}Xe, and ^{142}Cs performed with Modular Total Absorption Spectrometer (MTAS) on-line mass-separated ion beams. These radioactivities were assessed by Nuclear Energy Agency as having high priority for decay heat analysis during nuclear fuel cycle. observe substantial increase in β feeding to excited states all daughter isotopes comparison earlier data. This...
Independent yields of 139 individual secondary (appearing after neutron evaporation) fragment pairs five different charge splits ${(Z}_{L}{/Z}_{H}=$46/52, 44/54, 42/56, 40/58, and 38/60) have been experimentally measured by detecting the coincidences between prompt $\ensuremath{\gamma}$ rays emitted in spontaneous fission ${}^{252}\mathrm{Cf}.$ Nuclear mass distributions fragments that follow from are consistent with similar previously known more integral data. Another type data extracted is...
From $\ensuremath{\gamma}$-ray coincidence studies following spontaneous fission of ${}^{252}\mathrm{Cf}$, direct measurements yields and neutron multiplicities were made for Sr-Nd, Zr-Ce, Mo-Ba, Ru-Xe, Pd-Te correlated pairs. A strong enhancement the 7-10 channels Mo-Ba pairs is observed. new mode associated with enhanced identified. These data can be interpreted in terms one or more ${}^{144,145,146}\mathrm{Ba}$ being hyperdeformed at scission. Mean field calculations predict a third...
New level schemes of odd-$Z$ $^{105,107,109}\mathrm{Tc}$ are proposed based on the $^{252}\mathrm{Cf}$ spontaneous-fission-gamma data taken with Gammasphere in 2000. Bands levels considerably extended and expanded to show rich spectroscopic information. Spin/parity configuration assignments made determinations multipolarities low-lying transitions analogies previously reported levels, those neighboring $\mathrm{Rh}$ isotopes. A non-yrast negative-parity band built...
The isotopic yields for the spontaneous cold fission of $^{252}\mathrm{Cf}$ are predicted by using a double-folding potential and M3Y nucleon-nucleon forces. penetrabilities through this barrier obtained within one-dimensional WKB approximation. Realistic fragment ground-state deformations used calculations. results in good agreement with zero neutron channel extracted from \ensuremath{\gamma}-\ensuremath{\gamma}-\ensuremath{\gamma} coincidence studies recorded early implementation...
Half-lives ${T}_{1/2}$ of states in $^{95,97}\mathrm{Sr}$, $^{97,100,104}\mathrm{Zr}$, $^{106}\mathrm{Mo}$, and $^{148}\mathrm{Ce}$, which decay by delayed \ensuremath{\gamma} transitions, were determined using a new time-gated triple coincidence method. Transition energy dependent effects such as time walks, jitters, amplitude possible timing fluctuations Ge detectors that contribute to the width window taken into consideration comparing prompt cascades with similar transition energies. It...
New level schemes of odd-Z99,101Y (Z = 39) and 101,105Nb 41) are established based on the measurement prompt gamma rays from fission 252Cf at Gammasphere. Bands π5/2+[422], π5/2−[303] π3/2−[301] observed extended to provide spectroscopic information concerning nuclear shapes in this important odd-Z region. In combination with structure Tc 43), Rh 45) neighbouring even-Z isotopes systematics, signature splittings kinematic dynamic moments inertia bands Y Nb discussed terms shape transition...
High-spin states in 70,72Se have been extended up to spin 14+ and 28+, respectively. The yrast bands both nuclei exhibit a very regular rotational pattern the highest spins observed, with no indication of band crossings above hw approximately=0.5 MeV. According deformed shell modeling calculations structures can be associated aligned configurations involving g9/2 quasiparticles.