Description of deep inelastic transfer reactions at the Fermi energy within transport models

Abstract

The possibility of studying the dissipative processes near the Fermi energy using the transport equations arising within the Boltzmann-Nordheim-Vlasov approach is discussed. It is shown that this approach makes it possible to reproduce all the main features of deep inelastic collisions of heavy ions: specifically, the deviation curves for reaction fragments and their Coulomb and nuclear rainbows and the strong correlation between the fragment exit angle and kinetic energy loss. The theoretical results are compared with the experimentally obtained data on the isotopic and velocity distributions of light fragments escaping at small angles in the 18O + 181Ta and 18O + 9Be reactions at an energy of 35 MeV/nucleon. It is established that the experimental velocity distributions contain two components: dissipative (with a velocity smaller than that of the projectile ion) and direct (having a maximum at the particle beam velocity). It is shown that the transport equations describe well the dissipative part of the reaction, which is about 30% of the total output. The direct component arises during fission of the projectile ion nucleus and is described well within the Goldhaber model.