620 research outputs found
Deducing spectroscopic factors from wave-function asymptotics
In a coupled-channel model, we explore the effects of coupling between
configurations on the radial behavior of the wave function and, in particular,
on the spectroscopic factor (SF) and the asymptotic normalization coefficient
(ANC). We evaluate the extraction of a SF from the ratio of the ANC of the
coupled-channel model to that of a single-particle approximation of the wave
function. We perform this study within a core + n collective model, which
includes two states of the core that connect by a rotational coupling. To get
additional insights, we also use a simplified model that takes a delta function
for the coupling potential. Calculations are performed for 11Be. Fair agreement
is obtained between the SF inferred from the single-particle approximation and
the one obtained within the coupled-channel models. Significant discrepancies
are observed only for large coupling strength and/or large admixture, that is,
a small SF. This suggests that reliable SFs can be deduced from the
wave-function asymptotics when the structure is dominated by one configuration,
that is, for a large SF.Comment: Title correcte
Observation of the Mott Effect in Heavy Ion Collisions
Possibility of observing the Mott momentum in the distribution of the
deuterons produced in the process , in the first stage of
a nuclear reaction is presented. The correlation of a hard photon with a
deuteron allows to select those deuterons produced at the beginning of a
reaction.Comment: 10 pages, 5 Postscript figure
Experimental and analytical performance investigation of air to air two phase closed thermosyphon based heat exchangers
In recent years, the use of wickless heat pipes (thermosyphons) in heat exchangers has been on the rise, particularly in gas to gas heat recovery applications due to their reliability and the level of contingency they offer compared to conventional heat exchangers. Recent technological advances in the manufacturing processes and production of gravity assisted heat pipes (thermosyphons) have resulted in significant improvements in both quality and cost of industrial heat pipe heat exchangers. This in turn has broadened the potential for their usage in industrial waste heat recovery applications. In this paper, a tool to predict the performance of an air to air thermosyphon based heat exchanger using the ε-NTU method is explored. This tool allows the predetermination of variables such as the overall heat transfer coefficient, effectiveness, pressure drop and heat exchanger duty according to the flow characteristics and the thermosyphons configuration within the heat exchanger. The new tool's predictions were validated experimentally and a good correlation between the theoretical predictions and the experimental data, was observed. © 2014 Elsevier Ltd. All rights reserved
Towards the 3D-Imaging of Sources
Geometric details of a nuclear reaction zone, at the time of particle
emission, can be restored from low relative-velocity particle-correlations,
following imaging. Some of the source details get erased and are a potential
cause of problems in the imaging, in the form of instabilities. These can be
coped with by following the method of discretized optimization for the restored
sources. So far it has been possible to produce 1-dimensional emission source
images, corresponding to the reactions averaged over all possible spatial
directions. Currently, efforts are in progress to restore angular details.Comment: Talk given at the Int. Workshop on Hot and Dense Matter in
Relativistic Heavy Ion Collisions, March 24-27, 2004, Budapest; 10 pages, 6
figure
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