10,829 research outputs found
Specific heat at constant volume in the thermodynamic model
A thermodynamic model for multifragmentation which is frequently used appears
to give very different values for specific heat at constant volume depending
upon whether canonical or grand canonical ensemble is used. The cause for this
discrepancy is analysed.Comment: Revtex, 7 pages including 4 figure
Radial flow has little effect on clusterization at intermediate energies in the framework of the Lattice Gas Model
The Lattice Gas Model was extended to incorporate the effect of radial flow.
Contrary to popular belief, radial flow has little effect on the clusterization
process in intermediate energy heavy-ion collisions except adding an ordered
motion to the particles in the fragmentation source. We compared the results
from the lattice gas model with and without radial flow to experimental data.
We found that charge yields from central collisions are not significantly
affected by inclusion of any reasonable radial flow.Comment: 8 pages, 2 figures, submitted to PRC; Minor update and resubmitted to
PR
Comparison of Canonical and Grand Canonical Models for selected multifragmentation data
Calculations for a set of nuclear multifragmentation data are made using a
Canonical and a Grand Canonical Model. The physics assumptions are identical
but the Canonical Model has an exact number of particles, whereas, the Grand
Canonical Model has a varying number of particles, hence, is less exact.
Interesting differences are found.Comment: 12 pages, Revtex, and 3 postscript figure
Negative specific heat in a thermodynamic model of multifragmentation
We consider a soluble model of multifragmentation which is similar in spirit
to many models which have been used to fit intermediate energy heavy ion
collision data. In this model is always positive but for finite nuclei
can be negative for some temperatures and pressures. Furthermore,
negative values of can be obtained in canonical treatment. One does not
need to use the microcanonical ensemble. Negative values for can persist
for systems as large as 200 paticles but this depends upon parameters used in
the model calculation. As expected, negative specific heats are absent in the
thermodynamic limit.Comment: Revtex, 13 pages including 6 figure
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