E. Tomasi

Investigation of the 40Ar + 197Au, 238U systems at 44 MeV/u

Abstract We have measured the angular correlation between two fragments emitted in the reactions Ar + Au and Ar + U at 44 MeV/u at GANIL. The aim was to investigate the amount of initial linear momentum transferred from the projectile to a fissioning nucleus. It turned out that this amount is much smaller than can be extrapolated from previous experiments. Furthermore, the probability of forming a fissioning nucleus is very small.

Linear momentum transfer investigated in the 20Ne + 197Au and 209Bi systems at 30 MeV/u

Abstract We have measured at SARA the correlation of fission fragments produced in the reactions 20 Ne + 197 Au and 20 Ne + 209 Bi at 30 MeV/u. The results show that the most probable amount of linear momentum transferred from the projectile to the fissioning nucleus is about 80 %. This corresponds to about 3.7 GeV/ c . The fission cross section is still rather large at this bombarding energy: 1.6±0.3 b for the Au target and 2.2±0.5 b for the Bi one. We present the results of a Monte-Carlo simulation which allows us to reproduce most of the experimental data under certain conditions which are discussed.

Calculation of interaction potentials between two heavy ions at finite temperature

Abstract Nuclear densities at finite temperature are generated by a modified hot Thomas-Fermi model. They are used to calculate hot interaction potentials. A simple dynamical calculation performed with these hot potentials show an enhancement of the fusion cross section at high bombarding energies.

Investigation of linear momentum transfer on the 35 MeV/u Ar+U system

We have measured, at GANIL, the angular correlation between two fission fragments in the reaction Ar+U at 35 MeV/u. The results are discussed in terms of the maximum energy that a nucleus can carry.

Investigation of linear momentum transfer on the20NeJ197Au system at 30 MeV/A

We have deduced the linear momentum transferred from the projectile to the fissioning nucleus in the reaction20Ne+197Au at 30 MeV/A by measuring the folding angle between the two fission fragments. We found that the most probable linear momentum transfer represents 76% of the initial value.

Real part of the nuclear interaction potential between α or p and excited heavy nuclei

Abstract We investigate, within a very simple double folding model, the nuclear interaction potential between α or p and excited heavy nuclei. The densities of the excited nuclei are calculated using a modified hot Thomas-Fermi model. Simple analytical expressions of the results are presented. The consequences of this calculation on evaporation probabilities is qualitatively discussed.

Spherical time dependent Thomas-Fermi calculation of the dynamical evolution of hot and compressed nuclei

We have used a self-consistent time dependent Thomas-Fermi model at finite temperature to calculate the dynamical evolution of hot and compressed nuclei. It has been found that nuclei can accomodate more thermal energy than compressional energy before they break.

Nucleon currents between highly excited nuclei: (II). Influence of the relative motion

Abstract A finite-temperature Thomas-Fermi method has been used to study the nucleon flux between two hot semi-infinite slabs of nuclear matter in arbitrary relative motion. As an application, we estimate the imaginary part of the optical potential associated with nucleon transfer at the strong absorption radius. Analytical fits to the exact results are given for head-on and tangential collisions at zero temperature.

Nucleon currents between highly excited nuclei

Abstract A finite temperature Thomas-Fermi method has been used to study the nucleon transfer between two hot slabs of symmetric nuclear matter. Special attention has been paid to temperature effects neglected in earlier calculations. As a result, closed and ready-to-use formulas for the exchange and transfer nucleon flux at zero relative momentum are given as a function of the temperature.

Spurious continuum effects on excited giant resonances

Abstract Using a fully variational time-dependent Thomas-Fermi (TDTF) model, we show the spurious influence of the external nucleon gas on the calculated finite temperature ( T ) isoscalar monopole strength function. This effect, which is independent of the multipolarity of the resonance, is very likely present in other more microscopic approaches to finite temperature giant resonances.