It is shown that the experimentally determined emission temperatures and source radii defining the density of the transient nuclear system at breakup are compatible with the predictions of the statistical multifragmentation model. The consideration of the Coulomb expansion and the evaporation processes of the clusters explains why the apparent temperature following from a Maxwell-Boltzmann fit to the fragment’s energy spectra is considerably larger than the so-called emission temperature.

• Received 29 June 1987

DOI:https://doi.org/10.1103/PhysRevC.37.2910