Observations on Lithium and Beryllium Nuclei Ejected from Heavy Nuclei by High Energy Particles

The yields of ${\mathrm{Be}}^7$ produced by 335-Mev protons on nuclei of different atomic number have been determined and found to decrease with increasing atomic number. Reactions are described in which the irradiation of an element with protons or alpha-particles results in products higher by three in atomic number. These reactions are interpreted tentatively as second-order processes in which the initial step is the production of high energy lithium nuclei, which in turn cause nuclear reactions of the type ($\mathrm{Li},xn$). From the observed over-all yields, deductions are made as to the cross sections for the separate steps.