Production cross sections for intermediate mass fragments from dynamical and statistical decay ofprojectile-like fragments in $^{124}$Sn + $^{64}$Ni and $^{112}$Sn + $^{58}$Ni collisions at 35 A MeV
Résumé
Background: In heavy-ion collisions at intermediate energies the production of light charged particles andintermediate mass fragments (IMFs) is due to different reaction mechanisms and different time scales, rangingfrom fast dynamical processes to statistical emission from the equilibrated system.Purpose: We compare the IMF statistical and dynamical emission probabilities in collisions of a neutron-rich$^{124}$Sn + $^{64}$Ni system and a neutron-poor $^{112}$Sn + $^{58}$Ni system at the laboratory energy of 35 A MeV.Method: The IMFs production mechanism in semiperipheral reactions has been investigated in our previousworks. In this paper, the analysis is expanded for the same set of data and production cross sections have beenevaluated for dynamical and statistical emission in a coherent way for light and heavy fragments.Results: The data analysis has evidenced a strong competition between dynamical and statistical emissionmechanisms. Probability of the dynamical emission of IMFs is strongly influenced by the (N/Z) ratio of thecolliding system.Conclusions: It is demonstrated that the statistical emission is equally probable for the two systems, whilethe dynamical emission is enhanced for the neutron-rich system, especially for heavy fragments (Z>6). Theobserved effect points at a high sensitivity of the prompt-dynamical emission to the (N/Z) ratio of a givensystem.
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...