9,390 research outputs found
Fabrication of large ceramic electrolyte disks
Process for sintering compressed ceramic powders produces large ceramic disks for use as electrolytes in high-temperature electrolytic cells. Thin, strain-free uniformly dense disks as large as 30 cm squared have been fabricated by slicing ceramic slugs produced by this technique
Superdeformations in Relativistic and Non-Relativistic Mean Field Theories
The applications of the extensions of relativistic mean field (RMF) theory to
the rotating frame, such as cranked relativistic mean field (CRMF) theory and
cranked relativistic Hartree-Bogoliubov (CRHB) theory, for the description of
superdeformed bands in the , 140-150 and 190 mass regions are
overviewed and compared briefly with the results obtained in non-relativistic
mean field theories.Comment: 18 pages including 5 figures in PostScript, requires epsf.sty,
invited talk presented at the International Conference on Achievements and
Perspectives in Nuclear Structure, Crete, Greece, July 11-17, 1999, will be
published in Physica Script
Properties of superdeformed fission isomers in the cranked relativistic Hartree-Bogoliubov theory
The rotational and deformation properties of superdeformed fission isomers in
the mass region have been investigated within the framework of the
cranked relativistic Hartree-Bogoliubov theory. The dependence of the results
of the calculations on the parametrization of the RMF Lagrangian has been
studied. The rotational properties are best described by the NL1 force.Comment: 5 pages, uses epsf.sty and hip-artc.sty, 1 PostScript figure,
contribution to the Proceedings of the International Symposium on Exotic
Nuclear Structures, May 15-20, 2000, Debrecen, Hungar
Cranked relativistic Hartree-Bogoliubov theory: Superdeformation in the mass region
A systematic investigation of the yrast superdeformed (SD) rotational bands
in even-even nuclei of the mass region has been performed within
the framework of the cranked relativistic Hartree-Bogoliubov theory. The
particle-hole channel of this theory is treated fully relativistically, while a
finite range two-body force of Gogny type is used in the particle-particle
(pairing) channel. Using the well established parameter sets NL1 for the
Lagrangian and D1S for the Gogny force, very good description of experimental
data is obtained with no adjustable parameters.Comment: 5 pages, 2 Postscript figures, uses sprocl.sty, contribution to the
Proceedings of the International Conference ``Bologna 2000, Structure of the
Nucleus at the Dawn of the Century'
Quasiparticle-vibration coupling in relativistic framework: shell structure of Z=120 isotopes
For the first time, the shell structure of open-shell nuclei is described in
a fully self-consistent extension of the covariant energy density functional
theory. The approach implies quasiparticle-vibration coupling for superfluid
systems. One-body Dyson equation formulated in the doubled quasiparticle space
of Dirac spinors is solved for nucleonic propagators in tin isotopes which
represent the reference case: the obtained energies of the single-quasiparticle
levels and their spectroscopic amplitudes are in agreement with data. The model
is applied to describe the shell evolution in a chain of superheavy isotopes
120 and finds a rather stable proton spherical shell
closure at Z = 120. An interplay of the pairing correlations and the
quasiparticle-phonon coupling gives rise for a smooth evolution of the neutron
shell gap between N = 172 and N = 184 neutron numbers. Vibrational corrections
to the alpha decay energies reach several hundred keV and can be either
positive and negative, thus also smearing the shell effects.Comment: 10 pages, 3 figure
Squeezing as an irreducible resource
We show that squeezing is an irreducible resource which remains invariant
under transformations by linear optical elements. In particular, we give a
decomposition of any optical circuit with linear input-output relations into a
linear multiport interferometer followed by a unique set of single mode
squeezers and then another multiport interferometer. Using this decomposition
we derive a no-go theorem for superpositions of macroscopically distinct states
from single-photon detection. Further, we demonstrate the equivalence between
several schemes for randomly creating polarization-entangled states. Finally,
we derive minimal quantum optical circuits for ideal quantum non-demolition
coupling of quadrature-phase amplitudes.Comment: 4 pages, 3 figures, new title, removed the fat
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