A beryllium target has been bombarded with 12-Mev protons, 24-Mev deuterons, and 48-Mev alpha particles. With the three projectiles, the differential cross sections for inelastic scattering leading to the formation of the 2.43-Mev state have been measured. Application of inelastic-scattering theory leads to the assignment for this level, spin $\frac{5}{2}$ and odd parity.

A very weak inelastic proton group has been found which could correspond to a level in ${\mathrm{Be}}^9$ at ∼1.8 Mev. The observation of inelastic alpha-particle groups corresponding to levels at 6.8 and 11.3 Mev makes definite the assignment of isotopic spin ½ to these states. The data obtained are not inconsistent with the existence of levels at 3.1 and 4.8 Mev.

The pickup reaction ${\mathrm{Be}}^9(p, d){\mathrm{Be}}^8$ (ground state) was observed. Although the distribution is peaked forward as predicted by Butler, the shape is the same as that found at other energies. Such behavior is not consistent with the quantitative aspects of the theory.

The reactions ${\mathrm{Be}}^9(p, n{p}^{\prime }){\mathrm{Be}}^8$ and ${\mathrm{Be}}^9(\alpha , n{\alpha }^{\prime }){\mathrm{Be}}^8$ have been studied. Analysis of the angular distributions suggests that those processes in which the charged particle retains most of the energy occur predominantly by direct interaction.

Finally, the elastic scattering of protons, deuterons, and alpha particles has been observed. Analysis of these distributions assuming a black nucleus gives reasonable agreement with the positions of the diffraction effects. The radii of interaction that are necessary are large but consistent within themselves and with those that fit the inelastic data.

• Received 24 October 1957

DOI:https://doi.org/10.1103/PhysRev.109.1591