E. Fabrici

Monte Carlo calculations of heavy ion cross-sections based on the Boltzmann Master equation theory

Abstract We describe Monte Carlo calculations which use as input the double differential multiplicities of the particles emitted in small time intervals during the thermalization of excited nuclei. These multiplicities are evaluated by solving a set of coupled Boltzmann Master equations. The comparison of the experimental and the predicted exclusive spectra of the nucleons emitted in symmetric and asymmetric complete fusion heavy ion reactions at incident energies of a few tens of MeV / amu shows that the calculations reproduce accurately the data.

Angular distributions and forward recoil range distributions of residues created in the interaction of 12C and 16O ions with 103Rh

Abstract We have measured the angular distributions and the forward recoil range distributions of residues produced in the interaction of, respectively, 151, 228 and 402 MeV 12 C ions with 103 Rh and the forward recoil range distributions of residues produced in the interaction of 303 MeV 16 O ions with 103 Rh. These data have been successfully reproduced by a theory which assumes that the dominant mechanisms are complete and incomplete fusion of the projectile with the target and single nucleon transfers from the projectile to the target and predicts that, starting from an incident energy of about 250 MeV, a large fraction of the residues has a mass and charge very close to those of the target nucleus. This is because, at incident energies of a few hundred MeV, a large fraction of the kinetic energy of 12 C and 16 O is carried away by fast ejectiles which then leave behind the intermediate equilibrated nuclei with a rather small excitation energy and small forward linear momentum.

A study of the effective interaction by the 15N(3He, t)15O reaction at incident energies between 16.5 and 37.7 MeV

Abstract Angular distributions for six triton groups, produced in the 15 N( 3 He, t) 15 O reaction, have been studied in the incident energy range 16.5–37.7 MeV. Data on 3 He elastic and inelastic scattering have been also collected. Optical model parameters have been deduced; the ambiguities in the geometries, strengths and in the energy dependence seem to be correlated. Macroscopic calculations give a satisfactory description to the isobaric analog state transition by using a complex symmetry potential; a large energy dependence of the surface imaginary term is required. A microscopic analysis is also given. Evidence for the need of a tensor term in the effective interaction has been found. The energy dependence, of exponential type, seems to be similar for all the isospin-dependent terms of the microscopic effective interaction.

Heavy ion interactions from Coulomb barrier to few GeV/n: Boltzmann Master Equation theory and FLUKA code performances

Results which have been recently obtained with the Boltzmann master equation and the FLUKA code in the analysis of heavy ion interactions at relative energies ranging from Coulomb barrier up to a few GeV/n are discussed.

Comprehensive studies of heavy ion reactions

45-MeV/Amu {sup 12}C reactions with nuclei such as {sup 63,65}Cu are analyzed. Relative cross sections and ranges are shown. The calculated isobar yield distribution includes a large number of unobserved residues. Little of the projectile energy is transferred to the target nucleus.

Towards a Comprehensive Description of Heavy Ion Reactions

Comprehensive analysis of heavy ion reactions at low and intermediate energies is made using the Boltzmann Master Equation theory and a Relativistic Quantum Molecular Dynamics model, respectively. As an example of the large variety of applications of such a study, a result concerning space radiation protection is presented.

Alpha Particle Emission in the Interaction of 400 MeV 12C with 59Co and 93Nb

Inclusive double differential cross sections of a particles emitted in the interaction of 400 MeV 12 C ions with59Co and 93 N were measured at several emission angles between 10°and 140°These spectra are satisfactorily reproduced in a priori calculations by considering the contributions of the spectator a particles produced in 12C break-up, the participant α particles which have been re-emitted with most of their energy after incomplete fusion reactions, the pre-equilibrium a particles which are mainly produced in complete fusion reactions, and the α particles which evaporated from the equilibrated nuclei produced at the end of the fast stage of the de-excitation process.

Boltzmann Master Equation Theory of Nuclear Reactions: From Nucleons to Heavy Ions

A large number of experimental results have shown that in reactions induced by nucleons or light particles at energies of the order of a few tens MeV, the great majority of the processes one observes are of statistical nature though they cannot be interpreted as a consequence of the decay of a fully equilibrated compound nucleus. In fact one observes the emission of ejectiles with energy greatly exceeding that expected in the evaporation from the compound nucleus, mostly emitted at forward angles instead of having angular distributions either isotropic or symmetric around 90°