The cross sections for ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ produced in fragmentation of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ by protons of 150 and 600 MeV and $\alpha$ particles of 880 MeV have been measured by mass spectrometry. The proton-induced cross sections are significantly larger than previous measurements at 600 MeV. The $\alpha$-induced cross sections are roughly a factor of 2 larger than the proton results. The implications of the new cross sections to the problem of light-element (Li, Be, B) production in cosmic rays are discussed.

• Received 9 May 1972

DOI:https://doi.org/10.1103/PhysRevC.6.685