Experimental investigation of the residues produced in the Xe-136+Pb and Xe-124+Pb fragmentation reactions at 1A GeV

The nuclide cross sections and longitudinal velocity distributions of residues produced in the reactions of Xe-136 and Xe-124 at 1A GeV in a lead target were measured at the high-resolution magnetic spectrometer, the fragment separator (FRS) of GSI. The data cover a broad range of isotopes of the elements between Z=3 and Z=56 for Xe-136 and between Z=5 and Z=55 for Xe-124, reaching down to cross sections of a few microbarns. The velocity distributions exhibit a Gaussian shape for masses above A=20, while more complex behavior is observed for lighter masses. The isotopic distributions for both reactions preserve a memory on the projectile N/Z ratio over the whole residue mass range.