NUCLEAR-REACTIONS OF TI, FE, CO, NI, CU, AND ZN BY 500-MEV PROTONS

Formation cross sections of product nuclides in the nuclear reactions of Ti, Fe, Co, Ni, Cu, and Zn targets by 500-MeV protons were measured with a Ge(Li)-gamma-ray spectrometer. The measured cross sections in the mass range between A approximately-equal-to 40 and A approximately-equal-to A(T) - 4 were used in the charge-dispersion analysis, where A(T) is the mass number of the target nucleus. The N/Z ratio of the charge-dispersion peak was found to be consistent with those obtained in the same mass range of spallation products in the nuclear reactions of the same medium-mass targets with 12-GeV protons. The mass-yield curve falls sharply with decreasing masses of product nuclides in contrast to relatively flat distributions at higher energies.