Scattering of 7.5-Mev Protons by Helium

The differential cross section for the elastic scattering of 7.5±{}0.1 Mev protons from helium has been measured at 2.5^∘{} intervals over the laboratory angular range 10^∘{} to 172.5^∘{} using the Los Alamos nuclear plate camera. The results obtained have an absolute standard error of ±{}2.5% to ±{}3%. A phase-shift analysis of the data gives for the S, P, and D phase shifts: δ₀=-57.95^∘, δ₁⁺=112.1^∘, δ₁^-=52.51^∘, δ₂⁺=0.44^∘, δ₂^-=-1.87^∘. These results fit the experimental data with a root-mean-square deviation of 2.7% and appear to be in harmony with those determined from experiments at other energies.