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The break-up of 156 MeV6Li ions colliding with12C,60Ni,90Zr,120Sn and208Pb has been experimentally studied. It was found that the break-up cross section decreases rapidly with increasing emission angles of the fragments and increases with increasing target mass. It comprises a fairly large fraction of the total reaction cross section. The observed features suggest that the6Li fragmentation is mainly a peripheral process, and is dominated by the cluster properties of the incident projectile. A simple plane-wave break-up model gives a rather good description of the shapes of the break-up bumps. The angular distributions of the fragments emitted in the6Li+208Pb reaction reveal the transition from peripheral break-up to incomplete fusion processes by which beam-velocity fragments are captured by the target nucleus. In addition to the (a+d) dissociation the (3He+t) break-up has been observed, but the triton spectra appear to be rather complex indicating further components due to more complicated reaction paths.

Excited levels of143Eu have been investigated by nuclear spectroscopy methods. We measured ?-rays and conversion electron singles spectra as well as??-coincidences from mass separated143mGd sources (108 s) prepared after the irradiation of144Sm with 78 MeVa-particles. In addition in-beam data were obtained by measuring?-ray singles spectra, angular distributions and??-coincidences, following the144Sm(a, 4n+ p, ?) reaction. A level scheme for143Eu comprising 19 levels is proposed, spin assignments or at least restrictions are given. The deduced experimental level scheme can be reproduced semiquantitatively by a generalized decoupling model which takes into account an asymmetric deformation of the core and a variable moment of inertia. Additionally, the results are discussed in the limit of the weak coupling model.

Excitation functions of the compound nuclear reactions191+193Ir,197Au(6Li,xn+yp) forx =3–13 andy=0–2 have been investigated by means of in-beam?-ray spectroscopy at the 156 MeV6Li beam of the Karlsruhe Isochronous Cyclotron. The beam energy has been varied in the range of 48 to 156 MeV in steps of about 10 MeV by Be-absorber foils in the external beam line. Absolute cross sections have been determined by normalizing the measured?-ray intensities to the production cross sections ofK- X-rays in the target. The experimental excitation functions are discussed on the basis of predictions of the preequilibrium (hybrid) model. While in most cases the theoretical calculations fairly well reproduce energy position and shapes of the curves, strong discrepancies in the absolute scale of the cross sections are observed. The theoretical predictions overestimate the (6Li,xn) cross sections by a factor of about 6. Conspicuous anomalies have been detected when comparing the (6Li, xn+1(2)p) reactions with (6Li,xn) reactions. The reactions with emission of one or two protons are considerably enhanced. The discrepancies and anomalies observed are tentatively explained by the influence of direct reaction channels as the6Li break-up, which experimentally proved to be the dominant contribution to the total reaction cross section. The enhancement of the reactions with emission of protons may be a consequence of transfer reactions into highly excited states combined with compound nucleus formation thus implying a cluster effect in preequilibrium emission process.

Intermediate mass fragment cross-sectionss(E, ?, 4=Z=11) have been measured in the reaction6Li+46Ti at 156 MeV incident energy. A simple sequential binary decay model describes most of theZ>8 data as evaporation from the compound nucleus. The complete fusion cross-section is also well reproduced. An intermediate velocity source model (ß=2ßCN, T=7 MeV) has been used in order to explain the small angle and Z=8 data which indicate aZ-4.1 dependence.

Precisely measured differential cross sections for elastic and inelastic scattering from 104 MeV alpha-particles by48Ca,50Ti and52Cr are reported. The analyses aim primarily at the determination of strength, radial shapes and deformation of the scattering potentials, looking for isotonic differences ofN=28 isotones. The mean square radii of the (real) potentials are discussed in terms of mean square radius differences of the matter distributions. The isoscalar transition rates derived by coupled channel analyses of the measured cross sections are compared with electromagnetic rates. In addition to the analyses on the basis of a slightly generalized extended optical model a semi-microscopic deformed folding model has been applied, using a density-dependent effective alpha-bound nucleon interaction. Though an excellent description of the data over the full angular range is obtained the resulting values of the deformation parameters appear to be not consistent with results from various different methods.

Single nucleon transfer reactions in collisions of 156 MeV6Li ions with6Li nuclei, leading to unstable final nuclei (5Li,5He) have been experimentally studied. The measured6Li(6Li,7Li)5Ligr and6Li(6Li,7Be)5Hegr differential cross sections have been analysed on the basis of a FR-DWBA procedure, looking to which extent the entrance channel optical potentials may account for the unknown exit channel potentials.