Differential elastic and inelastic scattering cross sections were measured for 10-Mev protons on beryllium, using a nuclear-emulsion technique. The Minnesota linear proton accelerator was used to provide a well-collimated monoenergetic beam. The results for elastic scattering are compared with other experiments, on the basis of a simple optical model, showing that, although the variation of elastic scattering cross section with angle is similar to that of other light elements, there are quantitative differences. The results on inelastic scattering are shown to be consistent with the currently accepted odd parity, $J=\frac{3}{2} or \frac{5}{2}$, for the 2.4-Mev. state of ${\mathrm{Be}}^9$. It appears, however, that a complex model of the ${\mathrm{Be}}^9$ nucleus will be required to explain the results in detail. The ($p, d$) reaction cross section for ${\mathrm{Be}}^9$ is also mentioned briefly.

• Received 30 March 1956

DOI:https://doi.org/10.1103/PhysRev.103.186