G. Giuliani

Coulomb corrections to density and temperature of bosons in heavy ion collisions

A recently proposed method, based on quadrupole and multiplicity fluctuations in heavy ion collisions, is modified in order to take into account distortions due to the Coulomb field. This is particularly interesting for bosons produced in heavy ion collisions, such as

LIGHT CLUSTERS EMISSION IN NUCLEAR REACTIONS AT 25 MeV/NUCLEON WITH DIFFERENT N/Z OF ENTRANCE CHANNELS

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Dynamical and thermodynamical properties of incomplete fusion events at 25 MeV/nucleon

and

The N/Z key role on the dynamics of medium mass nuclear systems near fragmentation threshold

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N/Z effects on dynamics of Ca+Ca collisions at 25 MeV/nucleon

particles. We derive temperatures and densities seen by the bosons and compare to similar calculations for fermions. The resulting energy densities agree rather well with each other and with the one derived from neutrons. This suggests that a common phenomenon, such as the sudden opening of many reaction channels and/or a liquid gas phase transition, is responsible for the agreement.

Isospin Aspects in Nuclear Reactions Involving Ca Beams at 25 MeV/nucleon

We discuss results on the emission of light clusters in nuclear reactions 40Ca + 40,48Ca,46Ti at 25 MeV/nucleon. They were detected and identified in mass and charge by means of the CHIMERA 4π array. Inclusive emission at forward angles shows that isotopic yields of Li and Be nuclei are related to the N/Z values of entrance channels. Moreover, structure effects and even-odd staggering in charge distributions of intermediate mass fragments emitted at forward angles will be shown. In agreement with previous experimental findings, odd-even effects are clearly visible in N ≈ Z systems, while are less pronounced in the neutron rich collision 40Ca+48Ca. These experimental findings are compared to preliminary data obtained in 40Ca+48Ca. collision at 25 MeV/nucleon.

Dynamical multi-breakup processes in the {sup 124}Sn+{sup 64}Ni system at 35 MeV/nucleon

Various aspects observed in the reactions 40Ca+40,48 Ca,46Ti at E=25 MeV/nucleon, studied by means of the CHIMERA detector, will be discussed. An isospin effect on the competition between heavy residue production and binary-like channels has been observed in incomplete fusion events. From the thermodynamical point of view, kinetic energy spectra of protons emitted in fusion-evaporation events were fitted with two maxwellian functions. Despite of the different neutron richness of the populated sources, the average temperatures obtained for the quasi-fused systems are similar (T≃5.2MeV). We also performed a preliminary reconstruction of the excitation energy reached by quasi-fusion sources populated in the studied reactions.

Isospin dependence of incomplete fusion reactions at 25 MeV/nucleon.

Effects related to the neutron to proton ratio (N/Z) degree of freedom in nuclear collisions 40Ca + 40Ca, 40Ca + 48Ca and 48Ca + 48Ca at 25 MeV per nucleon, analyzed by means of the Chimera multi-detector, have been investigated. Strong isotopic effects are found in mass distributions of light isotopes. Moreover, the competition between various reaction mechanisms at semi-central impact parameters seems to be influenced by the neutron richness of the total system formed.

Even-odd effects in Z and N distributions of fragments emitted at intermediate energies

Semi-central events of collisions 40,48Ca +40,48 Ca at 25 MeV/nucleon have been investigated by means of the Chimera multi-detector array. We find that the competition between evaporation residue and two or more fragment emission is regulated in a strong way by the neutron to proton ratio of the total reaction system. Comparisons of experimental data and Constrained Molecular Dynamics model calculations allow to obtain information about the behavior of the symmetry energy of the nuclear Equation of State.

Pre-equilibrium {gamma}-ray emission induced in the {sup 40}Ca+{sup 48}Ca system at 10 MeV/nucleon and isospin equilibration processes

Isospin dependence of dynamical and thermodynamical properties observed in reactions 40Ca+ 40,48Ca and 40Ca + 46Ti at 25 MeV/nucleon has been studied. We used the CHIMERA multi-detector array. Strong isospin effects are seen in the isotopic distributions of light nuclei and in the competition between different reaction mechanisms in semi-central collisions. We will show also preliminary results obtained in nuclear collision 48Ca + 48Ca at 25MeV/nucleon, having very high N/Z value in the entrance channel (N/Z = 1.4). The enhancement of evaporation residue production confirms the strong role played by the N/Z degree of freedom in nuclear dynamics.