A coincidence method of studying the scattering of protons by protons has been developed and applied to the 8-Mev protons obtained from the Princeton cyclotron. Relative measurements of the scattering cross section as a function of the angle of scattering are most consistent with theoretical cross sections calculated, assuming $S$ wave scattering only. However, the accuracy of the experiment is not great enough definitely to exclude $P$ wave scattering effects, positive or negative. An absolute measurement of the scattering cross section has been made and the experimental value 1.7±.1×${10}^{-25\mathrm{}}$ ${\mathrm{cm}}^2$ agrees with the theoretical value 1.80×${10}^{-25\mathrm{}}$ cm to within the experimental uncertainty.

• Received 14 December 1946

DOI:https://doi.org/10.1103/PhysRev.71.339