EXCITATION OF THE 2-PHONON GIANT-DIPOLE RESONANCE IN U-238 STUDIED VIA INCLUSIVE MEASUREMENTS OF NEUTRON-REMOVAL CROSS-SECTIONS

As part of a comprehensive study of uranium fragmentation at relativis tic energies at the GSI projectile fragment separator, FRS, inclusive neutron-removal cross sections have been measured for several sn chann els at projectile energies of 600 and 950 A MeV. The electromagnetic c ross sections agree surprisingly well with a semiclassical calculation based on measured photonuclear cross sections and do not require an e xtra enhancement of the two-phonon giant dipole excitation as conclude d from similar measurements with Au-197.