  Characteristics of the primary fragments produced in central collisions of
129Xe + natSn from 32 to 50 AMeV have been obtained. By using the correlation
technique for the relative velocity between light charged particles (LCP) and
fragments, we were able to extract the multiplicities and average kinetic
energy of secondary evaporated LCP. We then reconstructed the size and
excitation energy of the primary fragments. For each bombarding energy a
constant value of the excitation energy per nucleon over the whole range of
fragment charge has been found. This value saturates at 3 AMeV for beam
energies 39 AMeV and above. The corresponding secondary evaporated LCP
represent less than 40% of all produced particles and decreases down to 23% for
50 AMeV. The experimental characteristics of the primary fragments are compared
to the predictions of statistical multifragmentation model (SMM) calculations.
Reasonable agreement between the data and the calculation has been found for
any given incident energy. However SMM fails to reproduce the trend of the
excitation function of the primary fragment excitation energy and the amount of
secondary evaporated LCP's.
