The angular distribution of the ${\mathrm{Be}}^9(p, d)$ reaction is substantially constant between 5 and 30 Mev. The Butler theory, used with a finite radius as cutoff on the radial integral, does not give a satisfactory interpretation of this fact, but the "transparent-nucleus" Born approximation pick-up theory does. For incident energies between 16 and 31 Mev this theory gives a momentum distribution for the picked-up neutron which is consistently defined, and which agrees quantitatively with that obtained from the 95-Mev data; at lower energies, 5 to 8 Mev, the theory does not appear to work quite as well. The results of the analysis give support to the general validity of interpreting results of the high-energy pick-up process in terms of a momentum distribution and a single-particle model.

• Received 19 December 1955

DOI:https://doi.org/10.1103/PhysRev.102.200