-The spallation residues produced in the bombardment of 56 F e at 1.5, 1.0, 0.75, 0.5 and 0.3 A GeV on a liquid-hydrogen target have been measured using the reverse kinematics technique and the Fragment Separator at GSI (Darmstadt). This technique has permitted the full identification in charge and mass of all isotopes produced with cross-sections larger than 10 −2 mb down to Z = 8. Their individual production cross-sections and recoil velocities at the five energies are presented. Production cross-sections are compared to previously existing data and to empirical parametric formulas, often used in cosmic-ray astrophysics. The experimental data are also extensively compared to different combinations of intra-nuclear cascade and de-excitation models. It is shown that the yields of the lightest isotopes cannot be accounted for by standard evaporation models. The GEMINI model, which includes an asymmetric fission decay mode, gives an overall good agreement with the data. These experimental data can be directly used for the estimation of composition modifications and damages in materials containing iron in spallation sources. They are also useful for improving high precision cosmic-ray measurements.

In the present work we were able to synthesize and measure with high accuracy the production cross sections of more than 190 heavy neutron-rich nuclei by the in-flight fragmentation of relativistic 208 Pb projectiles, 26 of which were produced for the first time. This work has shown that the N = 126 region far below the doubly magic 208 Pb has become accessible experimentally and represents a step further towards the study of heavy neutron-rich nuclei approaching the r-process waiting point at A = 195.

Production cross sections of medium-mass neutron-rich nuclei obtained in the fragmentation of 136 Xe projectiles at 1 A GeV have been measured with the FRagment Separator (FRS) at GSI. 125 Pd was identified for the first time. The measured cross sections are compared to 238 U fission yields and model calculations in order to determine the optimum reaction mechanism to extend the limits of the chart of the nuclides around the r-process waiting point at N=82.

The spallation of 56 Fe in collisions with hydrogen at 1 A GeV has been studied in inverse kinematics with the large-aperture setup SPALADIN at GSI. Coincidences of residues with low-center-ofmass kinetic energy light particles and fragments have been measured allowing the decomposition of the total reaction cross-section into the different possible de-excitation channels. Detailed information on the evolution of these de-excitation channels with excitation energy has also been obtained. The comparison of the data with predictions of several de-excitation models coupled to the INCL4 intra-nuclear 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. Spallation reactions play an important role in many domains ranging from astrophysics to intense neutron sources. Proton-induced reactions are also a way to study the de-excitation mechanism of a nucleus in a single hot source, and with less dynamical effects than in nucleusnucleus collisions. They are often described as a 2-step model, with an intra-nuclear cascade (INC) phase followed by a de-excitation phase. Inclusive data on light particles emitted in the spallation process and, more recently, data on spallation residues, helped considerably in improving the models [1]. However, these are not sufficient to provide a real insight into the reaction mechanism and the discrepancies observed between data and codes cannot be interpreted unambiguously with inclusive data. This is in particular due to the fact that the final observables are often both influenced by the cascade phase (especially by the remnant excitation energy) and by the de-excitation phase. A few more exclusive measurements exist but are generally limited to the study of the most violent collisions representing a small part of the total reaction cross-section (for a review see e.g. [2]).The need for a better understanding of spallation reactions motivated the design of the SPALADIN setup at GSI, which aims at measuring in inverse kinematics and in coincidence all the spallation products with a low center-of-mass (c.m.) kinetic energy, from neutrons to heavy residues. The restriction to low c.m. energies, in fact due to geometrical acceptance limitations, largely favors the detection of particles from the de-excitation rather than the cascade phase. This allows to use the particle multiplicities as an indication of the excitation energy (E ⋆ ) at the end of the cascade stage.The SPALADIN setup, partially described in [3], is based on the inverse kinematics technique where the ion beam is projected onto a liquid hydrogen target. The use of the large acceptance dipole magnet ALADIN permits to select the particles with a low c.m. kinetic energy. Among other detectors, the setup comprises the large area neutron detector LAND, which provides neutron multiplicities, a time-of-flight wall and the multitrack and multiple-sampl...

No abstract