Observation of theα-Particle Breakup Process atEαlab=172.5MeV

Abstract

Double-differential cross sections $\frac{d^2\sigma }{d\Omega \mathrm{dE}}$ have been measured for the ($\alpha$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) reaction on Ni isotopes at ${E_{\alpha }}^{\mathrm{lab}}=172.5\mathrm{}$ MeV. A distinct peak was found, having a half-width of ∼40 MeV and a strongly decreasing intensity with increasing reaction angle. Theoretical evidence is provided to attribute this peak to the ($\alpha$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) stripping process into the continuum.