Total Cross Sections of 208-Mev and 315-Mev Protons for Light Elements

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Transmission measurements were performed with an external collimated proton beam of The University of Chicago 170-inch synchrocyclotron. Total cross sections of the neutron and ten light elements (H and D, Li, B, Be, C, N, O, Al, S, and Cl) were measured by coincidence and anticoincidence methods at proton energies of 208 and 315 Mev at several subtended angles.The cross sections obtained include all processes except the Coulomb scattering, for which corrections were applied. The corrected cross sections, measured at different subtended angles (poor geometries) were plotted with their statistical uncertainties as a function of the solid angle subtended or of the angle, and extrapolated to zero degrees (good geometry).Only a limited number of previous investigations of the light elements at high particle energies have been made. The results found in the present study for the proton total cross sections for the various elements were comparable to the available published neutron total cross sections measured at the same energies.It was found, by application of the transparent optical model, that cross sections measured were consistent with a nuclear radius $R=1.23{A}^{\frac{1}{3}}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}$ cm and an absorption coefficient $K=0.5\ifmmode\times\else\texttimes\fi{}{10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}1}$.