Measurements have been made of the energy spectra and angular distributions of Li, Be, and B nuclei emitted from a Ni target bombarded with 3-GeV protons, using a counter telescope technique. By integrating the spectra and normalizing to the radiochemically determined cross section of ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$, total isotopic cross sections have been determined, and these are discussed in terms of the cosmic ray production of Li, Be, and B. The experimental cross sections are compared with a recent semiempirical formula; within the uncertainties the agreement between experiment and prediction is satisfactory.

NUCLEAR REACTIONS Ni with 3-GeV protons; measured energy spectra, angular distributions, yields for Li, Be, and B isotopes.

• Received 1 October 1974

DOI:https://doi.org/10.1103/PhysRevC.12.527