Isotopically resolved residues from the fragmentation of projectiles with largely different N/Z - the isospin-thermometer method

The mean N-over-Z (/Z) ratio of residues produced in the fragmentation of 136Xe (N/Z=1.519), 124Xe (N/Z=1.296) in comparison with 56Fe (N/Z=1.154) is investigated over the full range of Z. The final residues from the 136Xe projectile keep a memory on the initial N/Z. The idea to trace back the excitation energy of the fragment entering evaporation via direct exploration of the N/Z evolution in the evaporation process is investigated and applied to the data. The freeze-out temperature is deduced, which is consistent with the investigations of light and intermediate-mass fragments (IMF) in other experiments.