10 research outputs found
The first quadrupole excitations in spherical nuclei and nuclear pairing
Excitation energies and transition probabilities of the first 2+ excitations
in even lead, tin and nickel isotopes are calculated within the self-consistent
Theory of Finite Fermi Systems based on the Energy Density Functional by Fayans
et al. A reasonable agreement with available experimental data is obtained. The
effect of the density dependence of the effective pairing interaction is
analyzed in detail by comparing results obtained with volume and surface
pairing. The effect is found to be noticeable, especially for the 2+ energies
which are systematically higher at 200-300 keV for the volume paring as
compared with the surface pairing case, the latter being in a better agreement
with the data.Comment: Presented at International Conference on Nuclear Structure and
Related Topics, Dubna, July 2 - 7, 201
Phonon effects on the double mass differences in magic nuclei.
Theoretical Physic
The role of the boundary conditions in the Wigner-Seitz approximation applied to the neutron star inner crust
The influence of the boundary conditions used in the Wigner-Seitz
approximation applied to the neutron star inner crust is examined. The
generalized energy functional method which includes neutron and proton pairing
correlations is used. Predictions of two versions of the boundary conditions
are compared with each other. The uncertainties in the equilibrium
configuration (Z,R_c) of the crust, where Z is the proton charge and R_c the
radius of the Wigner-Seitz cell, correspond to variation of Z by 2 -- 6 units
and of R_c, by 1 -- 2 fm. The effect of the boundary conditions is enhanced at
increasing density. These uncertainties are smaller than the variation of Z and
R_c coming from the inclusion of pairing. The value of the pairing gap itself,
especially at high density, can depend on the boundary condition used.Comment: LaTeX, 11 pages, 3 figures, to be published in Phys. Lett.
High-Energy Ion Generation by Short Laser Pulses
This paper reviews the many recent advances at the Center for Ultrafast Optical Science (CUOS) at the University of Michigan in multi-MeV ion beam generation from the interaction of short laser pulses focused onto thin foil targets at intensities ranging from 1017 to 1019 W/cm2. Ion beam characteristics were studied by changing the laser intensity, laser wavelength, target material, and by depositing a well-absorbed coating. We manipulated the proton beam divergence using shaped targets and observed nuclear transformation induced by high-energy protons and deuterons. Qualitative theoretical approaches and fully relativistic two-dimensional particle-in-cell simulations modeled energetic ion generation. Comparison with experiments sheds light on ion energy spectra for multi-species plasma, the dependences of ion-energy on preplasma scale length and solid density plasma thickness, and laser-triggered isotope yield. Theoretical predictions are also made with the aim of studying ion generation for high-power lasers with the energies expected in the near future, and for the relativistic intensity table-top laser, a prototype of which is already in operation at CUOS in the limits of several cycle pulse duration and a single-wavelength spot size
Magnetic moments of thallium isotopes in the vicinity of magic N = 126
The magnetic dipole moments (μ) of 209Tlg (N=128) and 207Tlm (N=126) have been measured for the first time using the in-source laser resonance-ionization spectroscopy technique with the Laser Ion Source and Trap (LIST) at ISOLDE (CERN). The application of the LIST suppresses the usually overwhelming background of the isobaric francium isotopes and allows access to heavy thallium isotopes with A⩾207. The self-consistent theory of finite Fermi systems based on the energy density functional by Fayans et al. well describes the N dependence of μ for 1/2+ thallium ground states, as well as μ for the 11/2− isomeric states in europium, gold and thallium isotopes. The inclusion of particle-vibration coupling leads to a better agreement between the theory and experiment for μ(Tlg, Iπ=1/2+). It is shown that beyond mean-field contributions to μ cannot be neglected at least for thallium isotopes with Iπ=1/2+