A5077740519- Nuclear physics research studies
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- Advanced Chemical Physics Studies
- Advanced NMR Techniques and Applications
- Particle physics theoretical and experimental studies
- Rare-earth and actinide compounds
- Atomic and Subatomic Physics Research
- Nuclear reactor physics and engineering
- Quantum, superfluid, helium dynamics
- Inorganic Fluorides and Related Compounds
- X-ray Spectroscopy and Fluorescence Analysis
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Astro and Planetary Science
- Neutrino Physics Research
- Radioactive Decay and Measurement Techniques
- Radiation Detection and Scintillator Technologies
- Geophysics and Gravity Measurements
- High-Energy Particle Collisions Research
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
DEVCOM Army Research Laboratory
2015-2024
United States Army Combat Capabilities Development Command
2021-2024
University of Maryland, College Park
2014-2023
Argonne National Laboratory
2014-2023
National Centre for Nuclear Research
2019-2023
Istituto di Fotonica e Nanotecnologie
2023
Oak Ridge Associated Universities
2015-2018
Florida State University
2018
Washington University in St. Louis
2001-2012
Park University
2012
New sideband partners of the yrast bands built on pi(h11/2)nu(h11/2) configuration were identified in 55Cs, 57La, and 61Pm N = 75 isotones 134Pr. These form with 134Pr unique doublet-band systematics suggesting a common basis. Aplanar solutions 3D tilted axis cranking calculations for triaxial shapes define left- right-handed chiral systems out three angular momenta provided by valence particles core rotation, which leads to spontaneous symmetry breaking doublet bands. Small energy...
The neutron-rich nucleus $^{144}$Ba ($t_{1/2}$=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers $A$ less than 200. Until now, indirect evidence for such strong has been inferred from observations as enhanced $E1$ transitions and interleaving positive- negative-parity levels in ground-state band. In this experiment, strength was measured directly by sub-barrier, multi-step Coulomb excitation a post-accelerated 650-MeV beam on...
The yields of over 200 projectile-like fragments (PLFs) and target-like (TLFs) from the interaction (${E}_{\mathrm{c}.\mathrm{m}.}=450$ MeV) $^{136}\text{Xe}$ with a thick target $^{208}\text{Pb}$ were measured using Gammasphere off-line $\ensuremath{\gamma}$-ray spectroscopy, giving comprehensive picture production cross sections in this reaction. compared to predictions grazing model Zagrebaev Greiner quantitative metric, theory evaluation factor $\mathit{t}ef$. are adequate for describing...
Two distinct sets of chiral-partner bands have been identified in the nucleus 133Ce. They constitute a multiple chiral doublet, phenomenon predicted by relativistic mean field (RMF) calculations and observed experimentally here for first time. The properties these are good agreement with results based on combination constrained triaxial RMF theory particle-rotor model.
A pair of transverse wobbling bands has been observed in the nucleus $^{135}$Pr. The is characterized by $\Delta I$ =1, E2 transitions between bands, and a decrease energy confirms its nature. Additionally, transition from to three-quasiparticle band comprised strong magnetic dipole observed. These observations conform well results calculations with Tilted Axis Cranking (TAC) model Quasiparticle Triaxial Rotor (QTR) Model.
We report the first observation of ^{108}Xe→^{104}Te→^{100}Sn α-decay chain. The α emitters, ^{108}Xe [E_{α}=4.4(2) MeV, T_{1/2}=58_{-23}^{+106} μs] and ^{104}Te [E_{α}=4.9(2) T_{1/2}<18 ns], decaying into doubly magic ^{100}Sn were produced using a fusion-evaporation reaction ^{54}Fe(^{58}Ni,4n)^{108}Xe, identified with recoil mass separator an implantation-decay correlation technique. This is time radioactivity has been observed to heavy self-conjugate nucleus. A previous benchmark for...
The odd-odd Cs isotopes ${}^{128\ensuremath{-}134}\mathrm{Cs}$ have been investigated in search of chiral doublet bands. Two nearly degenerate bands built on the $\ensuremath{\pi}{h}_{11/2}\ensuremath{\bigotimes}\ensuremath{\nu}{h}_{11/2}$ configuration identified ${}^{128\ensuremath{-}132}\mathrm{Cs}.$ Systematics various experimental observables associated with partner are presented. ${B(M1)}_{\mathrm{In}}{/B(M1)}_{\mathrm{Out}}$ staggering spin was discovered to be phase $B(M1)/B(E2)$ for...
$^{9}\mathrm{Be}$-induced inelastic scattering of $^{62,64,66}\mathrm{Fe}$ and $^{60,62,64}\mathrm{Cr}$ was performed at intermediate beam energies. Excited states in $^{64}\mathrm{Cr}$ were measured for the first time. Energies population patterns excited these neutron-rich Fe Cr nuclei are compared interpreted framework large-scale shell-model calculations different model spaces. Evidence increased collectivity distinct structural changes between neighboring isotopic chains near $N=40$ is...
Excited states of ${}^{76}$Ge have been populated in above-barrier Coulomb excitation and inelastic scattering a 530-MeV beam on ${}^{238}$U target studied using in-beam $\ensuremath{\gamma}$-ray spectroscopy with the Gammasphere array. The $\ensuremath{\gamma}$ band was extended considerably one new identified. Comparisons collective- shell-model calculations suggest that may be rare example nucleus exhibiting rigid triaxial deformation low-lying states.
The quadrupole collectivity of low-lying states and the anomalous behavior $0^+_2$ $2^+_3$ levels in $^{72}$Ge are investigated via projectile multi-step Coulomb excitation with GRETINA CHICO-2. A total forty six $E2$ $M1$ matrix elements connecting fourteen were determined using least-squares search code, gosia. Evidence for triaxiality shape coexistence, based on model-independent invariants deduced from Kumar-Cline sum rule, is presented. These interpreted a simple two-state mixing model...
Three odd-odd $N=73$ isotones, namely ${}^{128}\mathrm{Cs},$ ${}^{130}\mathrm{La},$ and ${}^{132}\mathrm{Pr},$ have been studied via (HI, $\mathrm{xn}\ensuremath{\gamma})$ reactions. In all three cases, $\ensuremath{\Delta}I=1$ side bands of the $\ensuremath{\pi}{h}_{11/2}\ensuremath{\nu}{h}_{11/2}$ yrast were discovered. This extends systematic observation nearly degenerate doublet in neighboring $N=75$ isotones; these interpreted as resulting from chiral symmetry breaking intrinsic...
Nearly degenerate partner bands observed in $A\ensuremath{\sim}130$ odd-odd triaxial nuclei are interpreted as a manifestation of chirality the intrinsic reference frame. A phenomenological approach, based on core-particle-hole coupling model, has been developed to address experimental observables. This laboratory-frame which chiral symmetry restored, includes core, particle/hole single-particle Hamiltonian, and quadrupole-quadrupole interactions. The optimal model parameters investigated....
The collective wobbling mode, the strongest signature for rotation of a triaxial nucleus, has previously been seen only in few Lu isotopes spite extensive searches nearby isotopes. A sequence transitions N=94 Ta167 nucleus exhibiting features similar to those attributed bands nuclei now found. This band feeds into πi13/2 at relative energy that established and its dynamic moment inertia alignment properties are nearly identical i13/2 structure over significant frequency range. Given these...
The low-spin level scheme of ${}^{68}$Ni was investigated following two-neutron-knockout and multinucleon-transfer reactions. energy the first excited state determined to be ${E}_{x}({0}_{2}^{+})=1603.5(3)$ keV. Relative $B(E2)$ transition probabilities were deduced compared with shell-model calculations using several modern effective interactions. Theory reproduces data well, but indicates substantial mixing multi-particle, multi-hole configurations for lowest observed ${0}^{+}$ ${2}^{+}$ states.
Shape coexistence near closed-shell nuclei, whereby states associated with deformed shapes appear at relatively low excitation energy alongside spherical ones, is indicative of the rapid change in structure that can occur addition or removal a few protons neutrons. Near 68Ni (Z=28, N=40), identification shape hinges on hitherto undetermined transition rates to and from low-energy 0+ states. In 68,70Ni, new lifetimes branching ratios have been measured. These data enable quantitative...
Excited states in ${}^{64}$Ni, ${}^{66}$Ni, and ${}^{68}$Ni were populated quasielastic deep-inelastic reactions of a 430-MeV ${}^{64}$Ni beam on thick ${}^{238}$U target. Level schemes including many nonyrast established up to respective excitation energies 6.8, 8.2, 7.8 MeV the basis \ensuremath{\gamma}-ray coincidence events measured with Gammasphere array. Spin-parity assignments deduced from an angular-correlation analysis observed \ensuremath{\gamma}-decay patterns, but information...
The structure of semi-magic 2870Ni42 was investigated following complementary multinucleon-transfer and secondary fragmentation reactions. Changes to the higher-spin, presumed negative-parity states based on observed γ-ray coincidence relationships result in better agreement with shell-model calculations using effective interactions neutron f5/2pg9/2 model space. second 2+ (4+) states, however, can only be successfully described when proton excitations across Z=28 shell gap are included....
Lifetimes of states in a rotational-like $M1$ band ${}^{110}\mathrm{Cd}$ have been determined through Doppler-shift attenuation method measurement performed with the Gammasphere array. The deduced $B(M1)$ values, which agree well predictions tilted axis cranking model, clearly confirm that it has character shears band. Using semiclassical scheme coupling two long $j$ vectors we deduce information on strength and form effective interaction between constituent nucleons. These results are first...
Lifetimes of high-spin states in two $\ensuremath{\Delta}I=1$ bands and one $\ensuremath{\Delta}I=2$ band ${}^{109}\mathrm{Cd}$ have been measured using the Doppler shift attenuation method an experiment performed ${}^{96}\mathrm{Zr}{(}^{18}\mathrm{O},5n)$ reaction with GAMMASPHERE array. Experimental total angular momenta reduced transition strengths for both were compared tilted axis cranking (shears mechanism) predictions principal predictions, based on configurations involving proton...
Excited states have been populated in ${}^{108}\mathrm{In}$ and ${}^{110}\mathrm{In}$ complementary backed- thin-target experiments using the Stony Brook $8\ensuremath{\pi}\mathrm{Ge}$-detector arrays. The level schemes for both isotopes extended modified, including first observation of $\ensuremath{\Delta}I=2$ bands ${}^{110}\mathrm{In}.$ Lifetimes four $\ensuremath{\Delta}I=1$ one band measured Doppler-shift attenuation method. Experimental total angular momenta reduced transition...
The neutron-deficient mercury isotopes, $^{184,186}$Hg, were studied with the Recoil Distance Doppler Shift (RDDS) method using Gammasphere array and K\"oln Plunger device. Differential Decay Curve Method (DDCM) was employed to determine lifetimes of yrast states in $^{184,186}$Hg. An improvement on previously measured values up $8^{+}$ is presented as well first for $9_{3}$ state $^{184}$Hg $10^{+}$ $^{186}$Hg. $B(E2)$ are calculated compared a two-state mixing model which utilizes variable...