Results of 12.4-Mev Proton-Proton Scattering at 90°

The differential cross section in the center-of-mass system for 12.4-Mev proton-proton scattering has been determined in the neighborhood of a scattering angle of 90^∘{}. A photographic technique was used with a camera having cylindrical symmetry. The function $f(E)$ as defined by Bethe has been calculated for each of the three cross-section runs which were made. The average value of $f(E)$ as determined by the experiment agrees closely with the value predicted by a linear extrapolation from the results below 4 Mev.