[en] Proton singles and coincidence spectra are shown. Possible reaction mechanisms are discussed. Protons of very high energy are observed, but it is not clear that they are associated with a pre-equilibrium process since evaporation is not ruled out. 2 figures

[en] For numerous systems (light or light projectiles) the critical angular momentum l_cr does not exceed the value of l_bf=0, the angular momentum corresponding to the nuclear fission stability line due to centrifugal effects. For heavy systems were the fission is still observed l_cr may exceed l_bf=0 and corresponds to the so-called fast fission. In an experiment with the systems ²⁰Ne + ¹⁸⁵Re and ⁴⁰Ar + ¹⁶⁵Ho leading to the same compound nucleus ²⁰⁵At at 157 MeV excitation energy it was not possible to reveal the differences between the two processes from a comparison of the experimental results with the theoretical predictions. In order to achieve that a determination of the characteristic times of the two processes by means of a neutron clock was performed. This implied the measurement of multiplicity, energy and angular distributions of the neutrons emitted by the compound nucleus, the measurement of the analog properties of the neutrons emitted by excited fission fragments as well as the measurement of the properties of light charged particles emitted by the products of these reactions. The data of this experiments are now analysed. From the obtained results and by means of the code Gemimi it was possible to deduce the lifetime of the first compound system mentioned above as 7.2 x 10^-20 s while for the second system the code which can not reproduce the pre-fission multiplicity allowed to estimate from the post-fission multiplicity a characteristic time of 3.3 x 10^-20 s

[en] Energy spectra for deuterons in coincidence with the deep-inelastic and the quasi-elastic component of the Ne-like fragments are shown. The deuteron yield is higher for the deep-inelastic component. 2 figures

[en] First and second moments of the γ multiplicity are shown as a function of the laboratory energy of the light fragment formed in the reaction. Model calculations indicate that both energy and angular momentum are equilibrated exclusively through particle transfer. 2 figures

[en] The singles and coincidence yields are compared as a function of Z for relaxed plus quasi-elastic events. The differences between the spectra are understandable in terms of depletion of the binary coincidence yield due to secondary fission of the heavy fragment for Z > 82 (Z/sub light/ < 28). The light fragments show angular distributions expected from deep inelastic scattering. The fragments heavier than the projectile exhibit the transition to behavior consistent with fission or long-lived deep inelastic events. 1 figure

[en] By using Bragg curve spectroscopy, one can measure atomic number and energy of high energy heavy ions stopping in a gas-filled ionization chamber with longitudinal electric field. In this paper, we report on the results obtained with an isobutane filled detector. An energy resolution of 0.8% fwhm and a Z resolution of 2.7% fwhm were achieved for elastically scattered 300 MeV ⁴⁰Ar ions. We study the Bragg peak amplitude dependence on the energy of the incoming ions, a dependence presumably due to the Frisch grid screening inefficiency. The corrected Bragg peak spectrum of inelastically scattered 300 MeV ⁴⁰Ar ions exhibits a satisfactory Z separation around Z = 18. (orig.)

[en] Kinetic energy spectra, charge and angular distributions have been measured for thirty elements produced in the reactions of 401 and 460 MeV ₅₆Fe+₁₉₇Au and in the reaction of 470 MeV ₅₆Fe+sup(107,109)Ag. In addition, ß-ray multiplicities were measured at the 470 MeV bombarding energy for both targets at a limited number of angles. The charge distributions for the deep-inelastic component of these system increase monotonically with atomic number in the measured angular range, whereas, those for the quasielastic component are skewed toward Z-values below the projectile. The angular distributions for the Fe-induced reactions show a smooth evolution from a side-peaked to forward-peaked distributions with increasing mass transfer. This side peak is more intense and more persistent for mass transfers from the projectile to the target. In the quasielastic region the ß-ray multiplicity is observed to increase almost linearly with decreasing Q-value whereas for large negative Q-values it is essentially constant and independent of the exit channel mass asymmetry. Finally, angular distributions, angle-integrated charge distributions and ß-ray multiplicities have been compared with a diffusion model in which the dynamics of shape evolution, N/Z equilibration, angular momentum and energy exchange occur via one-body forces. (orig.)

[en] Singles and coincidence charge distributions are combined to illustrate the mechanism for the 220-MeV ⁴⁰Ar + ²³⁸U reaction. It is found that the apparent peak in the coincidence fragment distribution corresponding to Z = 82 (A=208) can be explained in terms of the fissionability of the target-like fragments produced in deep-inelastic collisions rather than as a manifestation of shell effects in compound-nucleus fission, as has been postulated for a similar system. (orig.)

[en] γ-ray multiplicities as a function of energy dissipation and mass asymmetry have been calculated from a diffusion model which simultaneously treats energy dissipation and angular momentum transfer on the basis of particle transfer. The good agreement obtained between the model calculations and the experimental multiplicities for ⁸⁶Kr-induced reactions on /sup 107,109/Ag, ¹⁶⁵Ho, and ¹⁹⁷Au targets lends credence to the one-body dissipation mechanism and l fraction along the mass-asymmetry coordinate

[en] A set of 43 momentum spectra from the inclusive reaction np→pX⁰ was measured with good statistical accuracy at 1.39, 1.56, 1.73 and 1.90 GeV/c (about 10 spectra per incident momentum), with a neutron beam obtained by stripping deuterons. The final proton was analysed in an angular region of between 0⁰ and 20⁰ in the laboratory by a magnetic spectrometer. The set of these results is analysed in terms of the pion exchange model using the parametrization of Duerr-Pilkuhn and Benecke-Duerr. The differential cross sections dsigma(np→pΔ⁰₃₃)/dt are determined from the experimental spectra. (Auth.)