Energy and Orbital Angular Momentum Dependence of Coulomb-Distorted (d, p) Angular Distributions

Abstract

Measurements are reported of the angular distributions of six proton groups from the ${\mathrm{Pb}}^{206}(d, p){\mathrm{Pb}}^{207}$ reaction obtained at deuteron energies of 12.5 and 14 Mev. When these measurements were combined with previously published measurements, the energy dependence of the experimental angular distributions of eight proton groups from this reaction was obtained over the range of bombarding energies from 8.3 to 15 Mev. These proton groups correspond to neutron capture by ${\mathrm{Pb}}^{206}$ with orbital angular momentum transfers of 0, 1, 2, 3, 4, and 6. Preliminary distorted-wave calculations are reported that are intended to provide a qualitative comparison with the experimental results. When the best distorted-wave fit is obtained for the angular distribution of the ground-state reaction at 14 Mev, qualitative fits for the energy dependence of this group and the $l$ dependence of other groups at 14 Mev are predicted by the theory without a change in parameters. With the particular parameters chosen, the predicted relative cross sections agree approximately with experiment with one exception; however the predicted absolute cross sections are too small. Different sets of deuteron parameters appear to give best fits to the elastic ($d, d$) and the ($d, p$) angular distributions, although a more extensive parameter search might yield a parameter set fitting both. The present comparison suggests that nuclear spectroscopic information may still be obtained in heavy elements by means of the deuteron stripping reaction, provided accurate experimental angular distributions are obtained with deuteron beams of high resolution and energies in the range of 15 to 25 Mev.