Interaction of 0. 6--300 GeV protons with U, Bi, Au, and Ag; mica track detector study

Mica track detectors were utilized to investigate interactions of 0.6-300 GeV protons with U, Bi, Au, and Ag. Fission cross sections of heavy elements are shown to remain nearly constant as the incident proton energy is increased from 13 to 300 GeV. The values of ${\ensuremath{\sigma}}_{f}$ for U, Bi, Au, and Ag at 300 GeV are 890 \ifmmode\pm\else\textpm\fi{} 130, 181 \ifmmode\pm\else\textpm\fi{} 35, 118 \ifmmode\pm\else\textpm\fi{} 24, and \ensuremath{\sim}1.3 mb, respectively. There is also no substantial change in the frequency of ternary relative to binary fission over this energy range; at 300 GeV it is about 0.4% for U, 1.1% for Bi, and 1.3% for Au. From observation of the forward to backward ratios of single (unpaired) tracks it was concluded that forward momentum transfer to heavy element targets peaks at \ensuremath{\sim}2 GeV and then decreases at higher beam energies.