Search results for "Nuclear Structure"
showing 10 items of 401 documents
Catalytic epoxidation using dioxidomolybdenum(VI) complexes with tridentate aminoalcohol phenol ligands
2019
Reaction of the tridentate aminoalcohol phenol ligands 2,4-di-tert-butyl-6-(((2 hydroxyethyl)(methyl)amino)methyl)phenol (H2L1) and 2,4-di-tert-butyl-6-(((1-hydroxybutan-2-yl)amino)methyl)phenol (H2L2) with [MoO2(acac)2] in methanol solutions resulted in the formation of [MoO2(L1)(MeOH)] (1) and [MoO2(L2)(MeOH)] (3), respectively. In contrast, the analogous reactions in acetonitrile afforded the dinuclear complexes [Mo2O2(μ-O)2(L1)2] (2) and [Mo2O2(μ-O)2(L2)2] (4). The corresponding reactions with the potentially tetradentate ligand 3-((3,5-di-tert-butyl-2-hydroxybenzyl)(methyl)amino)propane-1,2-diol (H3L3) led to the formation of the mononuclear complex [MoO2(L3)(MeOH)] (5) in methanol whi…
Variation of fundamental constants and 229Th
2017
The first excited state of the nucleus229Th has an exceptionally small excitation energy of7.8 eV, which is expected to be very sensitive to changes in the fine structure constant α.A small difference in the Coulomb energies of the two states, which both are of the order109eV, would amplify variations in α into large variations of the transition frequency.Hartree-Fock and Hartree-Fock-Bogoliubov calculations are performed to compute theCoulomb energies of the two states. The kinetic energies are also calculated which reflecta possible variation in the nucleon or quark masses or local Lorentz invariance violation. peerReviewed
Isovector and isoscalar spin-multipole giant resonances in the parent and daughter nuclei of double-β-decay triplets
2022
The strength distributions, including giant resonances, of isovector and isoscalar spin-multipole transitions in the commonly studied double-β-decay triplets are computed in the framework of the quasiparticle random-phase approximation (QRPA) using the Bonn-A two-body interaction in no-core single-particle valence spaces. The studied nuclei include the double-β parent and daughter pairs (76Ge, 76Se), (82Se, 82Kr), (96Zr, 96Mo), (100Mo, 100Ru), (116Cd, 116Sn), (128Te, 128Xe), (130Te, 130Xe), and (136Xe, 136Ba). The studied transitions proceed from the ground states to the Jπ=0−,1−,2− (spin-dipole transitions) and Jπ=1+,2+,3+ (spin-quadrupole transitions) excited states in these nuclei. Compa…
Low-lying electric dipole gamma-continuum for the unstable Fe-62,64 nuclei : Strength evolution with neutron number
2020
6 pags., 4 figs.
Coulomb excitation of 222Rn
2022
International audience; The nature of quadrupole and octupole collectivity in $^{222}$Rn was investigated by determining the electric-quadrupole (E2) and octupole (E3) matrix elements using subbarrier, multistep Coulomb excitation. The radioactive $^{222}$Rn beam, accelerated to 4.23 MeV/u, was provided by the HIE-ISOLDE facility at CERN. Data were collected in the Miniball $\gamma$ -ray spectrometer following the bombardment of two targets, $^{120}$Sn and $^{60}$Ni. Transition E2 matrix elements within the ground-state and octupole bands were measured up to 10 ¯h and the results were consistent with a constant intrinsic electric-quadrupole moment, 518(11) $e$ fm$^2$ . The values of the int…
International workshop on next generation gamma-ray source
2022
Journal of physics / G 49(1), 010502 (2022). doi:10.1088/1361-6471/ac2827
Thouless-Valatin Rotational Moment of Inertia from the Linear Response Theory
2017
Spontaneous breaking of continuous symmetries of a nuclear many-body system results in appearance of zero-energy restoration modes. Such modes introduce a non-physical contributions to the physical excitations called spurious Nambu-Goldstone modes. Since they represent a special case of collective motion, they are sources of important information about the Thouless-Valatin inertia. The main purpose of this work is to study the Thouless-Valatin rotational moment of inertia as extracted from the Nambu-Goldstone restoration mode that results from the zero-frequency response to the total angular momentum operator. We examine the role and effects of the pairing correlations on the rotational cha…
Commissioning of the BRIKEN beta-delayed neutron detector for the study of exotic neutron-rich nuclei
2017
Beta-delayed neutron emission (Beta-n) is a form of radioactive decay in which an electron, an anti-neutrino and one or more neutrons are emitted. This process arises if the energy window of the decay Q_Beta is greater than the neutron separation energy S n of the daughter. The probability in each decay of emitting neutrons is called the Pn value. This form of decay plays a key role in the synthesis of chemical elements in the Universe via the rapid neutron capture process, or r-process. The r-process proceeds far from the valley of nuclear stability, and leads to very neutron-rich nuclei that then decay to the line of stability. Most of these nuclei are ßn emitters. The initial abundance d…
Detailed spectroscopy of doubly magic $^{132}$Sn
2020
The structure of the doubly magic $^{132}_{50}$Sn$_{82}$ has been investigated at the ISOLDE facility at CERN, populated both by the $\beta^-$decay of $^{132}$In and $\beta^-$-delayed neutron emission of $^{133}$In. The level scheme of $^{132}$Sn is greatly expanded with the addition of 68 $\gamma$-transitions and 17 levels observed for the first time in the $\beta$ decay. The information on the excited structure is completed by new $\gamma$-transitions and states populated in the $\beta$-n decay of $^{133}$In. Improved delayed neutron emission probabilities are obtained both for $^{132}$In and $^{133}$In. Level lifetimes are measured via the Advanced Time-Delayed $\beta\gamma\gamma$(t) fas…
Total absorption γ-ray spectroscopy of the β-delayed neutron emitters 137I and 95Rb
2019
The decays of the β-delayed neutron emitters 137I and 95Rb have been studied with the total absorption γ-ray spectroscopy technique. The purity of the beams provided by the JYFLTRAP Penning trap at the ion guide isotope separator on-line facility in Jyväskylä allowed us to carry out a campaign of isotopically pure measurements with the decay total absorption γ-ray spectrometer, a segmented detector composed of 18 NaI(Tl) modules. The contamination coming from the interaction of neutrons with the spectrometer has been carefully studied, and we have tested the use of time differences between prompt γ rays and delayed neutron interactions to eliminate this source of contamination. Due to the s…