Nuclear Reactions of High-EnergyC12,N14, andO16with Carbon

The reactions of 160-Mev ${\mathrm{O}}^{16}$, 140-Mev ${\mathrm{N}}^{14}$, and 120-Mev ${\mathrm{C}}^{12}$ with ${\mathrm{C}}^{12}$ to yield radioactive products have been studied and the results compared with those for proton induced reactions giving formally similar compound systems. Excitation functions for products formed at lower energies are similar in the corresponding proton and heavy ion cases, indicating that their formation involved similar low energy, low spin compound nuclei. However, no "tail" due to knock-on cascade processes was observed with heavy ions. Yields for higher energy products, chiefly ${\mathrm{F}}^{18}$, were much higher in the heavy ion bombardments. This may be attributed partly to higher average energy deposition with heavy ions, due to the absence of knock-on processes, and partly to enhanced alpha emission from the distorted high-spin compound nuclei formed by heavy ions. The contribution of various stripping processes to these yields is discussed.