Isotopic composition of the residues produced in the fragmentation of $^{124}$Xe and $^{136}$Xe projectiles

The evolution of the N/Z degree of freedom in the fragmenting system has become an important observable in investigations of the properties of nuclear systems under extreme temperatures and densities. With the use of the high-resolution magnetic spectrometer, the FRagment Separator (FRS), at GSI Darmstadt, the residues up to the heavy projectile, produced in the fragmentation of $^{124}$Xe and $^{136}$Xe projectiles in a lead target at 1AGeV, were isotopically identified. The full isotopic distributions and mean N/Z ratios measured in these reactions will be presented. The isotopic composition of the final residues reveals a clear sensitivity to the N/Z ratio of the projectile. The sensitivity of the final isotopic composition of the measured residues to the competing emission of light particles and more complex clusters during evaporation and to the thermal conditions at the freeze-out of the break-up stage is investigated.