Alpha particles scattered from a helium gas target at an incident energy of 7.56 Mev have been observed in nuclear emulsions. The differential cross sections measured can be fitted with phase shifts of ${\delta }_0=70\mathrm{}°$ and ${\delta }_2=100\mathrm{}°$.

• Received 5 August 1959

DOI:https://doi.org/10.1103/PhysRev.117.531