Measurement of isotopic cross sections of spallation residues in 800 A MeV 197Au+p collisions Original Research Article

The spallation of 197Au by 800 MeV protons was investigated in inverse kinematics at GSI, Darmstadt, by use of a 197Au beam bombarding a liquid-hydrogen target. The fragment separator (FRS) was used to select and identify the reaction products prior to β decay. The individual production cross sections and the kinematic properties of 380 isotopes for all elements between mercury (Z=80) and neodymium (Z=60) have been measured. A comparison with a Monte-Carlo calculation based on the two-step model of the spallation reaction is given. The isotopic cross-section distribution of iridium isotopes is compared to that resulting from the aluminium-induced fragmentation of 197Au. The mean kinetic energies of the fragments are deduced from the experimental data. The importance of the new data to improve our understanding of the spallation mechanism is discussed.