Expansion and disassembly phase of energetic nuclear reactions: A problem of dynamical instabilities

The expansion phase of a hot nuclear system as created in an energetic heavy ion collision is calculated and discussed by a selfconsistent field-theoretical model which consideres dynamical growth of instabilities arising from strong fluctuations of the one-body density. First multiplicity distributions and mass spectra resulting from a series of numerical runs in a two dimensional model world are presented and discussed. (orig.)