Angular and Energy Correlations in the ReactionO16(α, 2α)C12g.s.at 40-MeV Incident Alpha-Particle Energy

The correlations in energy and angle of alpha particles produced in the reaction ${\mathrm{O}}^{16}(\alpha , 2\alpha ){{\mathrm{C}}^{12}}_{\mathrm{g}.\mathrm{s}.\mathrm{}}$ have been measured. Coincidence techniques were employed using semiconductor particle detectors and two-dimensional pulse-height analysis. The data show that a two-step reaction mechanism involving the formation and decay of excited states of ${\mathrm{O}}^{16}$ plays an important role. However, direct knock-out features of the reaction are also prominent and appear to be inextricably interwoven with its two-step aspects.