Global Representation of the Cross Sections for the Production of Fragments of UH Nuclei

Abstract

We have examined the fragmentation of relativistic iron, lanthanum, holmium and gold nuclei with energies between 500 and 1200 MeV/n incident on targets of polyethylene, carbon, aluminum, copper and lead. We have determined 1,256 elemental partial cross sections for the production of fragments from interactions in pure target materials. Deduced values have been found for another 417 cross sections in a hydrogen medium. The dependencies of these cross sections on energy, mass and charge have been studied. We have generated a seven parameter global fit to the cross sections for the heavy targets which fits a significant range of the data with a standard deviation of 7%. We have also generated a similar global fit to the cross sections for the hydrogen target which fits a slightly smaller range of the data with a standard deviation of 10%. These representations show that weak factorization can apply, but slightly better fits can be obtained without it. The mean mass losses observed for fragments that have lost a few protons, show that typically three or more neutrons are lost with each proton, producing fragment nuclei that must be highly proton rich, and consequently very unstable