Multifragmentation threshold in 93 Nb + nat Mg collisions at 30 MeV/nucleon
We analyzed the $^{93}Nb$ on $^{nat}Mg$ reaction at $30$ MeV/nucleon in the aim of disentangling binary sequential decay and multifragmentation decay close to the energy threshold, i.e. $\simeq 3$ MeV/nucleon. Using the backtracing technique applied to the statistical models GEMINI and SMM we reconstruct simulated charge, mass and excitation energy distributions and compare them to the experimental ones. We show that data are better described by SMM than by GEMINI in agreement with the fact that multifragmentation is responsible for fragment production at excitation energies around $3$ MeV/nucleon.
Influence of different binding energies in clusterization approach: fragmentation as an example
We study multifragmentation within the framework of a quantum molecular dynamics model using different binding energy formulae in the secondary algorithm; namely, the minimum spanning tree approach. A comparison of theoretical results with experimental data over a wide range of energy, mass and impact parameter is also presented. Our detailed analysis shows an insignificant difference of different binding energies when used at finite temperatures on the fragmentation pattern which, on the other hand, becomes significant when used for cold matter.
Mass scaling of reaction mechanisms in intermediate energy heavy ion collisions
Abstract Reaction mechanisms have been studied for two nearly symmetrical systems of different total mass, between 25 and 74 A MeV. It is shown that collisions are mostly binary whatever the system mass and the bombarding energy. From the slowing-down of the partners, it is possible to establish the continuous evolution from quasielastic to (completely) damped collisions. It turns out that results are independent of the total system mass if involved energies are expressed in A MeV. The occurrence of mid-rapidity emission is also considered and may be used to establish a link between mechanisms observed at low and high bombarding energy. Part of it corresponds to a fast decay of outgoing partners.