[en] The lithium 6 nucleus is a projectile of interest to study nuclear reactions at low energy due to the possibility to obtain high heats of reaction, and to its structure which can play an important role in the projectile-target interaction. This research thesis focused on the study of two low-energy reactions provoked by lithium projectiles. These reactions are studied within the framework of the theoretical model of aggregates. The first part presents the experimental conditions of both reactions, reports the development and analysis of nuclear plates, and the transformation of a given type of particle histogram into a spectrum in the mass centre system. The next parts report the study of the ⁶Li + ⁶Li reaction (previous results, kinematic analysis, spectrum of secondary particles, theoretical analysis of results) and of the ⁶Li + ¹⁰B reaction (previous results, experimental results, study of the continuous spectrum of alpha particle, reaction mechanisms)

[en] A summary of research is presented on the extent of nuclear clustering in lithium 6 in the reactions ⁶Li + X → ⁴He + ²H + X and ³He + ³H + X at 11.8 GeV. A list of publications is included

[en] We present a quantum reaction approach that unambiguously quantifies the complete and incomplete fusion of weakly-bound few-body nuclei. Calculations carried out within a simple model for "6Li + "2"0"9Bi at energies near the Coulomb barrier show that converged probabilities for the total, complete and incomplete fusion as well as for the scattering process can be obtained with the time-dependent wave-packet dynamics. (author)

[en] Results of measurement of residues formed in fusion of ⁶Li with ¹⁹⁸Pt in the energy range of 0.68< E/V_b<1.3 using a new sensitive off-beam technique are reported. The fusion excitation function and the derived average angular momenta do not indicate a change of slope at deep sub-barrier energies, contrary to recent observations. The present results for a system with weakly bound projectile confront the current understanding of the fusion hindrance at these low energies, underlying the role of internal reorganization on the dynamical path towards fusion.

[en] The problem of the calculation of inclusive breakup cross sections in nuclear reactions is reexamined. For that purpose, the theory proposed by Ichimura et al. (Phys Rev C 32:431, 1985) is revisited, both in its prior and post representations. We briefly outline the connection of this theory with that proposed by Udagawa and Tamura (Phys Rev C 24:1348, 1981) and apply both theories to the inclusive breakup of "6Li on "2"0"9Bi at near-barrier energies, comparing also with available data. The relative importance of elastic versus non-elastic breakup, as a function of the incident energy and of the projectile separation energy, is also investigated. (author)

No abstract available

[en] The cross section for the reaction ⁶Li + ⁶Li → ⁷Be + ⁴He + n + 1.91 MeV has been measured at effective energies of 5.0, 3.5, and 1.6 MeV. The resulting large cross sections are 178 +- 6.4, 93.4 +- 6.0, and 3.89 +- 0.39 mb, respectively. Irradiations of ⁶LiF targets were performed with a 6.0-MeV ⁶Li-ion beam at the 88-in. cyclotron of the Lawrence Berkeley Laboratory

No abstract available

[en] The ⁶Li + n seven-nucleon nuclear system is studied at low energies within a microscopic approach based on the multichannel algebraic version of the resonating group model. The partial and total cross sections for the ⁶Li(n, t)⁴He reaction are calculated. The contributions of the various partial cross sections to the energy dependence of the total cross section are considered. The results of the calculations are found to be in a good agreement with experimental data.

No abstract available