Differential ranges of Sc fragments from the interaction ofU238with 0.8-400 GeV protons

Differential ranges of ${}_{}{}^{44}{}_{}{}^{}\mathrm{Sc}_{}^m{}_{}{}^{}$ ${}_{}{}^{46}{}_{}{}^{}\mathrm{Sc}$, ${}_{}{}^{47}{}_{}{}^{}\mathrm{Sc}$, and ${}_{}{}^{48}{}_{}{}^{}\mathrm{Sc}$ emitted at 90° to the beam in the interaction of ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ with 0.8, 3.0, 11.5, and 400 GeV protons have been measured and transformed to the corresponding energy spectra. The mean fragment energies decrease from 83±5 to 58±4 MeV between 0.8 and 11.5 GeV and to 50±3 MeV at 400 GeV. The widths of the spectra increase markedly with energy up to 11.5 GeV and more slowly thereafter. Isotopic differences are minor although the spectra of neutron-deficient ${}_{}{}^{44}{}_{}{}^{}\mathrm{Sc}_{}^m{}_{}{}^{}$ are somewhat broader, particularly at 0.8 GeV. The results are compared with the statistical fragment emission model and discussed in terms of asymmetric binary fission and deep spallation mechanisms.