Interaction of Fast Negative Pions Withni60

The $\ensuremath{\gamma}$-ray spectra resulting from the bombardment of $^{60}\mathrm{Ni}$ and $^{28}\mathrm{Si}$ with 500-MeV/c negative pions were measured. For $^{60}\mathrm{Ni}$, lines were present from the decay of first excited states of $^{56}\mathrm{Fe}(^{60}\mathrm{Ni}\ensuremath{-}1\ensuremath{\alpha})$, $^{52}\mathrm{Cr}(^{60}\mathrm{Ni}\ensuremath{-}2\ensuremath{\alpha})$, and $^{48}\mathrm{Ti}(^{60}\mathrm{Ni}\ensuremath{-}3\ensuremath{\alpha})$. Single neutron removal was not observed. Similar results were obtained for $^{28}\mathrm{Si}$. A comparison is made with results obtained with stopped ${K}^{\ensuremath{-}}$ and proton beams.