244,515 research outputs found
Ion-retarding lens improves the abundance sensitivity of tandem mass spectrometers
Ion-retarding lens which increases the abundance sensitivity of tandem magnetic-analyzer mass spectrometers measures isotopes of low abundance in mass positions adjacent to isotopes of high abundance. The lens increases the abundance sensitivity for isotopes lying farther from high abundance isotopes than the energy cutoff of the lens
On the universality of some Smarandache loops of Bol-Moufang type
A Smarandache left (right) inverse property loop in which all its f; g- principal isotopes are Smarandache f; g- principal isotopes is shown to be universal if and only if it is a Smarandache left(right) Bol loop in which all its f; g- principal isotopes are Smarandache f; g- principal isotopes
Resonant photonuclear isotope detection using medium-energy photon beam
Resonant photonuclear isotope detection (RPID) is a nondestructive
detection/assay of nuclear isotopes by measuring gamma rays following
photonuclear reaction products. Medium-energy wideband photons of 12-16 MeV are
used for the photonuclear reactions and gamma rays characteristic of the
reaction products are measured by means of high-sensitivity Ge detectors.
Impurities of stable and radioactive isotopes of the orders of micro-nano gr
and ppm-ppb are investigated. RPID is used to study nuclear isotopes of
astronuclear and particle physics interests and those of geological and
historical interests. It is used to identify radioactive isotopes of fission
products as well.Comment: 6 pages, 3 figure
Isospin dependence of mass-distribution shape of fission fragments of Hg isotopes
Using an improved scission-point model, the mass distributions are calculated for induced fission of even Hg isotopes with mass numbers A=174 to 196. With increasing A of a fissioning AHg nucleus the mass distribution evolves from symmetric for 174Hg, to asymmetric for isotopes close to 180Hg, and back to more symmetric for 192,194,196Hg. In the fissioning Hg isotopes their excitation energy weakly influences the shape of the mass distribution. In 180,184Hg, the mass distributions of fission fragments remain asymmetric even at high excitation energies
Helium Clustering in Neutron-Rich Be Isotopes
Measurements of the helium-cluster breakup and neutron removal cross sections
for neutron-rich Be isotopes A=10-12,14 are presented. These have been studied
in the 30 to 42 MeV/u energy range where reaction measurements are proposed to
be sensitive to the cluster content of the ground-state wave-function. These
measurements provide a comprehensive survey of the decay processes of the Be
isotopes by which the valence neutrons are removed revealing the underlying
alpha-alpha core-cluster structure. The measurements indicate that clustering
in the Be isotopes remains important up to the drip-line nucleus 14^Be and that
the dominant helium-cluster structure in the neutron-rich Be isotopes
corresponds to alpha-Xn-alpha.Comment: 5 pages, 2 tables and 3 figure
Exotic Structure of Carbon Isotopes
We studied firstly the ground state properties of C-isotopes using a deformed
Hartree-Fock (HF)+ BCS model with Skyrme interactions. Shallow deformation
minima are found in several neutronrich C-isotopes. It is shown also that
the deformation minima appear in both the oblate and the prolate sides in
C and C having almost the same binding energies. Secondly, we
carried out shell model calculations to study electromagnetic moments and
electric dipole transitions of the C-isotopes. We point out the clear
configuration dependence of the quadrupole and magnetic moments in the odd
C-isotopes, which will be useful to find out the deformations and the
spin-parities of the ground states of these nuclei. We studied electric dipole
states of C-isotopes focusing on the interplay between low energy Pigmy
strength and giant dipole resonances.
Reasonable agreement is obtained with available experimental data for the
photoreaction cross sections both in the low energy region below =14 MeV and in the high energy giant resonance region (14 MeV 30 MeV).
The calculated transition strength below dipole giant resonance (14 MeV) in heavier C-isotopes than C is found to exhaust
about of the classical Thomas-Reiche-Kuhn sum rule value and
of the cluster sum rule value.Comment: 31 pages, 19 eps figure
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