Deep-inelastic heavy ion reactions are nowadays used in gamma spectroscopy studies of nuclei that cannot be populated in fusion–evaporation reactions. The planning of these spectroscopic experiments was initially guided by general understanding of the reaction mechanism of deep-inelastic heavy ion collisions acquired in earlier investigations which employed fragment detection techniques. However, it was early recognized that the knowledge of kinematics and dynamics of the colliding systems was not satisfactory for practical application of deep-inelastic reactions to nuclear spectroscopy. In particular, it was not straightforward to predict yields of populated fragments in order to select optimal experimental conditions such as the target-projectile combination and the collision energy.

I will review results of detailed product yield analysis for a few deep-inelatic collision experiments used for gamma spectroscopy. The most important feature determining the access to exotic neutron-rich nuclei is the neutron to proton (N/Z) ratio equilibration. Experimentally determined N/Z values for DIC products will be compared with expectations based on potential energy minimization and on Heavy-Ion Phase-Space Exploration (HIPSE) phenomenological model dedicated to heavy-ion reactions around Fermi energy. Conclusions drawn from the studied N/Z equilibration process show some limitations in reaching very exotic neutron-rich nuclei via this reaction mechanism.