New Evidence for a Direct Process in the (e, α) Reaction

Alpha-particle energy and angular distributions have been measured for the reaction ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}(e, \alpha )e^{\prime }X$ using electrons of energies 33, 60, and 120 MeV. Statistical-model calculations give good quantitative agreement in the region of the peak of the $\alpha$ energy spectra. Higher-energy $\alpha$ particles exhibit a forward-peaked angular distribution and a cross section several orders of magnitude above the statistical-model predictions, indicating the presence of a direct-reaction component.