[en] The study of nuclear multifragmentation is important for understanding the reaction mechanisms in heavy-ion collisions. In the present work, we study the nuclear reaction "1"2"9Xe + "n"a"tSn in the energy range E = 8 to 15 AMeV. This experiment was performed at GANIL with the multidetector INDRA.We study the charge distributions produced in this reaction, which are broad and cover a large atomic number range. By using the data of this experiment, we identify four channels differing by the number of fragments: 1, 2, 3 and 4 fragments. In this contribution we will show a method to reconstruct the average size and excitation energy of the primary fission fragments, before their decay. The method employed is based on the fragment-light charged particles relative velocity correlation functions. Preliminary results will be presented.

[en] High-energy transport codes are used in a large number of domains as spallation neutron sources or ADS design, space or medical applications. In these codes, nuclear models describing spallation reactions generate the necessary elementary cross-sections and characteristics of all the reaction products. During the last years, new high-quality experimental data have been collected leading to the development of more reliable spallation models, as the INCL4-ABLA combination of intranuclear cascade and de-excitation models, now available in MCNPX. However, remaining deficiencies have been identified, which can be of important consequences for applications, for instance in the prediction of damage. They generally originate from not well understood physics mechanisms. To solve these problems more constraining experiments are now being carried out, which allow a deeper understanding of the reaction mechanisms, in particular for the de-excitation stage. Recent improvements of INCL4 are presented. Impact for applications is discussed. (authors)

[en] The aim of this work is to develop a 3D gamma camera with high position resolution and sensitivity relying on both distance/absorption and Compton scattering techniques and without using any passive collimation. The proposed gamma camera is simulated in order to predict its performance using the full benefit of Geant4 features that allow the construction of the needed geometry of the detectors, have full control of the incident gamma particles and study the response of the detector in order to test the suggested geometries. Three different geometries are simulated and each configuration is tested with three different scintillation materials (LaBr3, LYSO and CeBr3)

[en] The A/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at SIS. A stable beam of ¹²⁴Sn and radioactive beams of ¹²⁴La and ¹⁰⁷Sn at 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. Chemical freeze-out temperatures are found to be nearly invariant with respect to the A/Z of the produced spectator sources, consistent with predictions for expanded systems. Small Coulomb effects (ΔT≅0.6 MeV) appear for residue production near the onset of multifragmentation

[en] In this work we have investigated the total fission cross section of ¹⁸¹Ta + ¹H at FRS (Fragment Separator - GSI) at 1, 0.8, 0.5 and 0.3 GeV with a specific setup, providing high accuracy measurements of the cross section values. the comparison of our data with previous results reveals a good agreement at high energies. However the situation remains unclear at lower energies. In general, our results covering a wide range of energy, are smoother. We have also compared the results obtained in this experiment, with several calculations performed with the intra-nuclear cascade model (INCL v4.1) coupled to de-excitation code (ABLAv3p), according to two different models describing fission process at high-excitation energies: statistical model of Bohr and Wheeler and the dynamical description of the fission process. We have showed that a simple statistical description largely over-predict the measured cross-section. Only a dynamical description of the fission, involving the role of the viscosity of the nuclear matter, provides a realistic result.

[en] Total fission cross sections of ¹⁸¹Ta ions colliding with hydrogen atoms at 300, 500, 800 and 1000 A MeV have been measured. The combined use of the inverse kinematics technique with an efficient detection set-up made it possible to determine these cross sections with high accuracy ranging between 8% and 17%. The new data put some light in the controversial results obtained so far and contribute to the understanding of the fission process at high excitation energies. (authors)

[en] The spallation of ⁵⁶Fe in collisions with hydrogen at 1A GeV has been studied in inverse kinematics with the large-aperture setup SPALADIN at GSI. Coincidences of residues with low-center-of-mass kinetic energy light particles and fragments have been measured allowing the decomposition of the total reaction cross section into the different possible deexcitation channels. Detailed information on the evolution of these deexcitation channels with excitation energy has also been obtained. The comparison of the data with predictions of several deexcitation models coupled to the INCL4 intranuclear cascade model shows that only GEMINI can reasonably account for the bulk of collected results, indicating that in a light system with no compression and little angular momentum, multifragmentation might not be necessary to explain the data

[en] In this experiment the spallation induced by 1 A GeV ⁵⁶Fe and ¹²C on a proton target is studied. The set-up is described and preliminary results are presented. (HSI)

[en] Spallation reactions are important due to their applications in various fields such as astrophysics, neutron sources, accelerator driven systems, and production of radioactive beams. To improve our understanding of the spallation mechanism a complete experiment, called SPALADIN, has been proposed, which aims at measuring as exclusively as possible the final states of the spallation reaction. This experiment has been performed at GSI using the spallation reactions 56Fe+p and 12C+p in reverse kinematics at 1 A GeV. The detection of the evaporation residues is performed with the ALADIN magnet and various detectors. The detection in coincidence of all the characteristics (type and energy) of the evaporation particles (neutrons and charged ones) and of the heavy residue should permit the reconstruction of the remnant prior to evaporation in mass, charge, and excitation energy. It will then be possible to test the modelisation of the first stage of the reaction. Furthermore it will allow study of the models describing the various decay modes of the primary residue like evaporation or Fermi break-up mechanisms for the lighter systems independently of the models of the first stage of the spallation reaction

[en] First coincidence data on the 56Fe+p reaction at 1 A.GeV in inverse kinematics obtained with the SPALADIN setup are presented. Data on charge correlations of cluster emissions occurring in the spallation reaction are shown and compared to spallation codes with the aim of discriminating between the various de-excitation mechanisms