Description
Poster session and refreshments
The $\beta$-decay of $^{125m,125,127}$Ag into levels in Cd was investigated at the Holifield Radioactive Ion Beam Facility (HRIBF) at ORNL. Uranium-238 targets were bombarded with 50-MeV protons with an intensity of 15 $\mu$A, and the induced fission products were mass separated ($\delta$M/M = 10,000) and deposited on a moving tape in the center of the VANDLE array consisting of...
The intricate process involved in the collective re-arrangement of nuclear fission dynamics is still an unconfirmed topic. A few systematic studies are present in the literature related to neutron multiplicities where the experimental data covers wide range of mass and energy. Pre-scission neutrons are extensively studied to understand fusion-fission dynamics involved in the population of...
The study of fission dynamics in the actinide region has gained a lot of importance because it can be helpful in providing crucial information about the challenges en route during the formation of superheavy nuclei. Although the intricate process involved in the collective re-arrangement of nuclear fission dynamics is still a unconfirmed topic. In the recent years synthesis of SHE is being...
N. Malekinezhad, M. R. Shojaei
aDepartment of Physics, Shahrood University of Technology, P.O. Box 3619995161-316, Shahrood, Iran.
E-mail: malekinezhadnasrin@gmail.com
shojaei_11151@yahoo.com
The non-relativistic motion of the nucleus in the Schrodinger equation and the relativistic motion in the Dirac and Klein-Gordon equations have long been known to be essential tools for studying atoms,...
Connecting Stellar Observations to Properties of Heavy Nuclei
Erika M. Holmbeck1,2,3
1Observatories of the Carnegie Institution for Science, 813 Santa Barbara St., Pasadena, CA 91101, USA
2Joint Institute for Nuclear Astrophysics -- Center for the Evolution of the Elements (JINA-CEE), 640 S Shaw Ln., East Lansing, MI 48824, USA
3Hubble Fellow
Nucleosynthesis by rapid neutron capture...
Photon-induced nuclear fission provides unique information about the nuclear fission process due to their selectivity on excitations of low multipolarity. In particular, fission induced by quasi-monochromatic polarized photons allows determining transition states and channels through which fission proceeds, learning about the nuclear energy landscape around the multi-humped fission barrier. To...
With the opening of the Facility for Rare Isotope Beams (FRIB) earlier this year, experiments have begun to study exotic neutron rich nuclei with the FRIB Decay Station Initiator (FDSi) [1], with first results obtained in the N=28 island of inversion [2]. The FDSi consists of two focal planes, one for discrete spectroscopy measurements using a hemisphere of gamma ray detectors and a second...
Dynamical pair production at sub-barrier energies
Thomas Settlemyre1, Aldo Bonasera2, and Hua Zheng3
1Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA
2Laboratori Nazionali del Sud, INFN, via Santa Sofia, 62, 95123 Catania, Italy
3School of Physics and Information Technology, Shaanxi Normal University, Xi’an 710119, China
In the collision of two heavy ions...
The $\beta$-decay strength function $S_{\beta}(E)$ governs [1,2] the nuclear energy distribution of elementary charge-exchange excitations and their combinations like proton particle $({\pi}p)$-neutron hole $({\nu}h)$ coupled into a spin-parity $I^{\pi}$: $[{\pi}p \otimes {\nu}h]I^{\pi}$ and neutron particle $({\nu}p)$-proton hole $({\pi}h)$ coupled into a spin-parity $I^{\pi}: [{\nu}p...
Fission dynamics of compound nuclei, primarily a collective phenomena, is elucidated through two intertwined aspects, the macroscopic (liquid drop) and the microscopic (shell) effects. Unanticipated observations of mass-asymmetric fission in 180Hg [1] and multimodal fission in 194,196Po, 202Rn [2] have led to the prediction of a new island of mass-asymmetric fission around the Pb region [3]....
The study of heavy-ion collisions around the Coulomb barrier offers an excellent opportunity to explore several spectacular effects which leads to a better understanding of reaction mechanisms as well as the sub-lime effects of nuclear structure. The fusion and Multi-Nucleon Transfer (MNT) reactions have been found to be elemental for the synthesis of exotic nuclei away from the valley of...
Submission for
Sanibel international conference ICFN7 Nov. 2022
IBM SU(3) symmetry versus BM rotor model
J .B. Gupta1 and J. H. Hamilton2
1Ramjas College, University of Delhi, Delhi-110007, India
2 Physics Department, Vanderbilt University, Nashville, TN 37235, U.S.A
The SU(3) symmetry in the interacting boson model sd IBM represent one of the three dynamical symmetry groups of the U(6)...
Neutron-rich nuclei 162,164Eu were produced by bombarding a proton beam on a 238U target at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory and mass seperating the 162,164Eu products. New level schemes and new gamma ray transitions of the daughters 162,164Gd were identified from beta-decay spectroscopy studies. Halflives of the 162,164Eu were remeasured to clarify...
Nuclei from the regions of doubly-closed shells are considered an excellent ground for studying both a) the couplings between valence nucleons - this provides information on the effective nucleon-nucleon interaction and, b) couplings of the valence nucleons with core excitations, what may be used as a unique test of various effective interactions.
$^{206}$Tl, having one-proton-hole and...
The Ni nuclei, with magic number $Z=28$, is considered as an interesting platform to study the evolution of shapes of nuclei as a function of neutron number. From the spherical shapes in $^56$Ni(N=28) and $^68$Ni(N=40) to the exhibition of super deformed bands in $^{63}$Ni[1] at high spin, different types of structure have been reported. Having the major shell closure at $Z=28$, the low lying...
Many-body tunneling involving strongly interacting particles is still not completely understood. The nuclear fission process is one example of many-body decay that can be represented as a tunneling process within the space of collective variables [1]. Using realistic potential energy surfaces obtained with the Hartree-Fock-Bogoliubov theory, we apply the nudged elastic band approach to...
see attachment
Fission is a fundamental nuclear decay that plays an important role in many areas of science. Recently, important progress has been made in microscopic modeling of the dynamics of spontaneous and induced fission based on the nuclear density functional theory (DFT) [1].
For this study, we investigate multi-modal fission pathways using nuclear DFT with several energy density functionals...
Neutron rich nuclei in the mass region around A=160 have been and will continue to be of interest for the study of nuclear structure because of the rapid onset of deformation between 88 and 90 neutrons. The observation of detailed changes in nuclear structures within this mass region has provided and will continue to provide insight into the nuclear force. Investigations of γ-rays emitted...
The structures of stretched excitations are dominated by a single particle-hole component for which the excited particle and the residual hole couple to the maximal possible spin value available on their respective shells. In light nuclei they appear as high-lying resonances resulting from the $p_{3/2} \rightarrow d_{5/2}$ stretched transitions. Due to the expected low density of other...
Level structures in neutron-rich 144Ba nucleus have been reinvestigated by measuring prompt 3 and 4 fold gamma rays emitted in the spontaneous fission fragments of 252Cf. The previous s = +1 octupole band structure with reflection asymmetric shape has been expanded. A new quadrupole band structure based on 3+ state with reflection symmetric shape has been identified. Decay pattern, angular...
Searches for electric dipole moments (EDMs) in atomic and molecular systems may provide better sensitivity to Time Reversal Invariance Violating (TRIV) interactions than neutron EDM due to enhancement factors related to complex structure of the system. We consider advantages and disadvantages of many-body nucleon system for the search for TRIV interactions in neutron scattering on heavy...
The theoretical and experimental observations conclude that the nuclei belonging to heavy and super heavy mass region may dissociate into two or three fragments at ground state as well as excited state. Two or three body decay depends on different nuclear properties such as shape, size, magicity etc. It was observed by Swiatecki et al.[1] that the fissility parameter can play a decisive factor...
Spin distribution measurements are one of the important aspects of heavy-ion induced studies. These measurements hold the information on maximum angular momentum that a nucleus can hold. Evaporation residue gated spin distribution in this mass region also becomes important because they help us to understand the dynamics of heavy-ion induced fusion-fission process. With knowledge gained from...
A puzzle has arisen recently caused by the apparent shift in maximum deformation from the expected $_{66}$Dy isotopic chain to the $_{60}$Nd isotopic chain in the $82
Observations of anomalously large abundances of stable Sr, Y, Zr, Mo, and Ru in some ultra-metal-poor (UMP) stars [1] as well as in the Galactic disk [2,3], as compared to heavier neutron-capture elements in the Solar System, have brought about new questions regarding the nucleosynthesis processes behind the production of those nuclei.
Comparison of observations with Galactic evolution...
Thermally enhanced alpha and cluster decay rates
D. F. Rojas-Gamboa1, N. G. Kelkar1, and O. L. Caballero2
1Departamento de Física, Universidad de los Andes, Carrera 1 No. 18 A - 10, Bogotá, 111711, Colombia
2Department of Physics, University of Guelph, Guelph, ON N1G 2W1, Canada
In a reaction network for the evolution of nuclear abundances, the thermal excitations of nuclei are...
To account for the observed abundances of heavy elements, the rapid-neutron capture process is essential [1]. It was first proposed more than six decades ago, but is still not completely understood. The r-process is thought to occur in very neutron rich environments such as neutron star mergers, where the fission yields play an important role in determination of the final abundances, in...
Kyle Beyer (1), Cole D. Pruitt (2), and Brian Kiedrowski (1)
(1) University of Michigan, Department of Nuclear Engineering and Radiological Sciences,
2355 Bonisteel Blvd, 1906 Cooley Bldg, Ann Arbor, Michigan 48109-2104
(2) Lawrence Livermore National Laboratory
7000 East Ave, Livermore, CA 94550
Fission event generators are used to study event-by-event correlations of emitted radiation in...
Neutron spectroscopy is an essential tool to probe the nuclear structure effects of neutron-rich nuclei, where beta-delayed neutron emission is a dominant decay mode. Neutron energies provide insights into the neutron unbound states in the emitter nuclei. The neutron energy spectrum measurement of the beta-delayed neutron precursor $^{24}O$ was performed for the first time at National...
The experimental yields of fragment mass and charge distributions for the neutron-induced fission of 30 actinide nuclei are well described in the model [1,2], which considers the fissioning scission system consisting of two heavy fragments and $\alpha$-particle between them. The $\alpha$-particle has its origin in the neck nucleons. The yield of fission fragments in the model is linked to the...
The properties of nuclear excitations can reveal many characteristics of the underlying nuclear structure. The low-lying collective excitations in the Mo isotopes in particular have been the subject of many theoretical and experimental studies. These nuclei have shown transitions from spherical, to deformed, to triaxial shapes when going toward the very neutron-rich isotopes. The great variety...
Submission for
Sanibel international conference ICFN7 Nov. 2022
Novel features of nuclear structure of Z = 46 Pd isotopes
J.B. Gupta1 and Joseph H. Hamilton2
1Ramjas College, University of Delhi, Delhi-110007, India
2 Physics Department, Vanderbilt University, Nashville, TN 37235, U.S.A
The A=100 and 130 region have been of current interest. The Z =46 Pd isotopes (N=54-70) display...
The nuclear level density (NLD) and nucleon emission spectra of the decay of compound nuclear systems has been a subject of tremendous interest for decades [1,2]. Some recent measurements of evaporation spectra of particles emitted from the highly excited compound nuclear systems provided [3,4] useful information about the interdependence of the NLD and excitation energy, isospin and spin...
Ushasi Datta,1,2, A.Rahaman1, S.Chakraborty1, A. Bhattacharyya1, T.Aumann3,4, S. Beceiro-Novo5, K. Boretzky3, C. Caesar3, B.V. Carlson6, D. Cortina-Gil5, P. Das1,2, J.Dey1,2, G. De. Angelis7, H. Emling3, H. Geissel3, M. Heine3, H. Johansson8, B. Jonson7, N. Kalantar-Nayestanaki9, T. Kr¨oll4, R. Kr¨ucken10, C. Langer3, Y. Leifels3, J. Marganiec3, G. M¨unzenberg3, T. Nilsson8, C....
