The elastic scattering of alpha particles from helium has been investigated at laboratory energies of 6.43, 6.84, and 7.78 Mev. Complete angular distributions from 20° to 90° in the center-of-mass system were obtained. Analysis of the data suggests somewhat smaller values for the $D$-wave phase shift then previously reported.

• Received 9 September 1960

DOI:https://doi.org/10.1103/PhysRev.121.580