Resonance Structure in ReactionBe9(d,γ)B11

The reaction ${}_{}{}^9{}_{}{}^{}\mathrm{Be}(d,\gamma ){}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ has been studied over the deuteron energy range of 0.56-3.56 MeV. A pulsed deuteron beam and time-of-flight electronics have been utilized to separate deuteron-capture $\gamma$ rays from events due to neutrons and cosmic rays. From a graphical analysis of the excitation functions for the ground, first, and combined second and third excited states, two resonances have been identified corresponding to ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ excitation energies of 17.44±0.05 and 18.37±0.05 MeV. The first of these occurs at the same energy as a level in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ found from other reactions. An interpretation in terms of $1s_{\frac{1}{2}}$ hole states is suggested. The overall behavior of the three excitation functions is used to justify a direct-capture reaction mechanism. Angular distributions were measured at 21 different deuteron energies. The near symmetry of the angular distributions about 90° and the peaking at 90° imply that a one-step deuteron-capture process is important for this reaction if the direct-capture mechanism is dominant. An appreciable forward peaking is observed for the first-excited-state angular distribution.