Grand canonical model predictions for nuclear fragmentation

The grand canonical ensemble has been used to make predictions for composite yields using simple models for nuclear fragmentation. While this gives correct model prediction for high energy collisions, it can give very inaccurate results at intermediate energy.

Figure 1

The yields in the multifragmentation model using the grand canonical ensemble and the canonical ensemble for $A=200$, $Z=80$. Note that the two ensembles give very different values at $T=4\mathrm{MeV}$.

Figure 2

The same as in Fig. 1 except for the system $A=50$, $Z=25$. Again note the discrepancies at $T=4.0\mathrm{MeV}$.