A simple model based on summing neutron-transfer diagrams is developed. This model gives a broad peak in the backward ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ elastic scattering cross section having some of the observed characteristics.

• Received 12 July 1971

DOI:https://doi.org/10.1103/PhysRevC.4.1968