N. T. Brewer
A5079766043- Nuclear physics research studies
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- Quantum Chromodynamics and Particle Interactions
- Nuclear reactor physics and engineering
- Atomic and Molecular Physics
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Advanced NMR Techniques and Applications
- Radioactive Decay and Measurement Techniques
- Rare-earth and actinide compounds
- Particle accelerators and beam dynamics
- Astro and Planetary Science
- Quantum, superfluid, helium dynamics
- High-pressure geophysics and materials
- Electron and X-Ray Spectroscopy Techniques
- Advanced Chemical Physics Studies
- Inorganic Fluorides and Related Compounds
- Crystallography and Radiation Phenomena
- Dark Matter and Cosmic Phenomena
- Metallurgy and Material Forming
- Mass Spectrometry Techniques and Applications
Oak Ridge National Laboratory
2016-2025
Vanderbilt University
2013-2024
University of Tennessee at Knoxville
2014-2024
Joint Institute for Computational Sciences
2015-2021
Hungarian Academy of Sciences
2018
Kurchatov Institute
2016
Université Libre de Bruxelles
2015
Tongji University
2015
We present results of the first experiment aimed at synthesis Mc isotopes in 243Am+48Ca reaction performed new gas-filled separator DGFRS-2 online to cyclotron DC280 Super Heavy Element Factory JINR. Fifty-five decay chains 288Mc and six assigned 289Mc were detected. The α 268Db with an energy 7.6–8.0 MeV, half-life 16+6−4h, a branch 55+20−15% was registered for time, spontaneously fissioning isotope 264Lr 4.9+2.1−1.3h identified. cross section 243Am(48Ca,3n)288Mc measured be 17.1+6.3−4.7...
The search for new decay chains of oganesson isotopes is presented. experiment utilized the Dubna Gas Filled Recoil Separator and a highly segmented recoil-decay detection system. signals from all detectors were analyzed in parallel by digital analog data acquisition systems. For first time, target mixed californium (51% $^{249}\mathrm{Cf}$, 13% $^{250}\mathrm{Cf}$, 36% $^{251}\mathrm{Cf})$ recovered decayed $^{252}\mathrm{Cf}$ sources was produced irradiated with an intense...
In this paper, we present results of the second experiment on synthesis Mc isotopes in $^{243}\mathrm{Am}+^{48}\mathrm{Ca}$ reaction performed at gas-filled separator DGFRS-2 SHE Factory JINR. The new isotope $^{286}\mathrm{Mc}$ was synthesized, and its half-life $20\begin{array}{c}+98\\ \ensuremath{-}9\end{array}$ ms \ensuremath{\alpha}-particle energy $10.71\ifmmode\pm\else\textpm\fi{}0.02$ MeV were determined. A $^{286}\mathrm{Mc} \ensuremath{\alpha}\text{\ensuremath{-}}\mathrm{decay}$...
Experiments using a $^{48}\mathrm{Ca}$ beam on $^{238}\mathrm{U}$ and $^{242}\mathrm{Pu}$ targets to produce superheavy nuclei were performed at the gas-filled separator DGFRS-2 online new cyclotron DC280 SHE Factory JINR. The decay properties of $^{286}\mathrm{Fl}$ $^{287}\mathrm{Fl}$, as well their \ensuremath{\alpha}-decay products, refined after detection 25 69 chains, respectively. In addition, 16 chains $^{283}\mathrm{Cn}$ observed in $^{238}\mathrm{U}+^{48}\mathrm{Ca}$ reaction....
We present new results from investigations of the $^{240}\mathrm{Pu}+^{48}\mathrm{Ca}$ reaction at a projectile energy 250 MeV. Three decay chains $^{285}\mathrm{Fl}$ were detected with properties mostly consistent those measured in earlier studies. An additional chain was observed where nuclei may through levels different other six registered so far. The cross section $^{240}\mathrm{Pu}$($^{48}\mathrm{Ca},3n$)$^{285}\mathrm{Fl}$ to be...
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...
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...
The conceptual design of the BRIKEN neutron detector at radioactive ion beam factory (RIBF) RIKEN Nishina Center is reported. setup a complex system aimed detecting heavy-ion implants, β particles, γ rays and β-delayed neutrons. whole includes Advanced Implantation Detection Array (AIDA), two HPGe Clover detectors up to 166 3He-filled counters embedded in high-density polyethylene moderator. quite due large number different types 3He-tubes involved additional constraints introduced by...
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,...
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"...
Abstract The β -delayed neutron-emission probabilities of 28 exotic neutron-rich isotopes Pm, Sm, Eu, and Gd were measured for the first time at RIKEN Nishina Center using Advanced Implantation Detector Array (AIDA) BRIKEN neutron detector array. existing -decay half-life ( T 1/2 ) database was significantly increased toward more isotopes, uncertainties previously values decreased. new data not only constrain theoretical predictions half-lives probabilities, but also allow probing mechanisms...
Background: An assessment done under the auspices of Nuclear Energy Agency in 2007 suggested that $\ensuremath{\beta}$ decays abundant fission products nuclear reactors may be incomplete. Many nuclei are potentially affected by so called pandemonium effect and their $\ensuremath{\beta}\text{\ensuremath{-}}\ensuremath{\gamma}$ decay heat should restudied using total absorption technique. The $^{137}\mathrm{I}$ $^{137}\mathrm{Xe}$ were assigned highest priority for restudy due to large...
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...
High spin states are observed for the first time in neutron-rich nuclei $^{151,153}\mathrm{Pr}$, $^{157}\mathrm{Sm}$, and $^{93}\mathrm{Kr}$ from spontaneous fission of $^{252}\mathrm{Cf}$. Twenty new transitions $^{151}\mathrm{Pr}$, twelve $^{153}\mathrm{Pr}$, five four were identified by using x-ray(Pr/Sm)-$\ensuremath{\gamma}$-$\ensuremath{\gamma}$ $\ensuremath{\gamma}$-$\ensuremath{\gamma}$-$\ensuremath{\gamma}$ triple coincidences. From measured total internal conversion coefficients...
Background: The very neutron-rich ${}^{150}$Ce is located at the edge of $Z=56$, $N=88$ octupole deformed island. Studying its high spin states and correlations important for systematically understanding nuclear structural characteristics in this region. Purpose: To investigate state levels to search octopole ${}^{150}$Ce. Methods: are studied by measuring prompt $\ensuremath{\gamma}$ rays spontaneous fission ${}^{252}$Cf. data analysis uses...
The $\ensuremath{\beta}$-decay properties of several neutron-rich germanium and arsenic isotopes were measured at the Holifield Radioactive Ion Beam Facility Oak Ridge National Laboratory. measurements almost-pure radioactive sources enabled by combination ion-source chemistry two-stage mass separation. half-life ${}^{86}$Ge ($226\ifmmode\pm\else\textpm\fi{}21$ ms) was determined for first time, while those ${}^{84,85}$Ge ${}^{84\ensuremath{-}87}$As remeasured. results are compared to...
We have reinvestigated the $\ensuremath{\beta}$ decay of ${}^{120}$Ag to levels in ${}^{120}$Cd. Significant deviations decays low-lying states from that expected a $\mathrm{U}(5)$ nucleus been observed. The results this paper which include 0${}_{2}^{+}$ and 3${}_{1}^{+}$ (which now correctly identified) previous work on lighter Cd isotopes strongly suggest anharmonic vibrator description even-even is inadequate. Analysis patterns half-life information led determination there are three...
The $\ensuremath{\beta}$ decay of $^{124,126}\mathrm{Ag}$ low- and high-spin isomers into levels in $^{124,126}\mathrm{Cd}$ was investigated. We have greatly expanded the schemes these nuclei including identification ${0}_{2}^{+}$ ${0}_{3}^{+}$ states among 63 new $^{124}\mathrm{Cd}$ ${2}_{2}^{+}$ state 30 $^{126}\mathrm{Cd}$. Several were identified $^{124}\mathrm{Cd}$, which based on energy are possible multiphonon states. Based states, we show that behave similar to lighter Cd isotopes...