The spectra of residual nuclei produced by the interaction of stopped and 45 MeV ${\pi }^{-}$ has been studied as a function of neutron excess in the nickel isotopes. The similarity of results for stopped pions and pions in flight indicates that absorption is the dominant mode of interaction. While the data show substantial departures from trends observed in measurements reported previously at higher energies, the same mechanism appears to explain the reaction in all cases.

NUCLEAR REACTIONS ${}_{}{}^{58,60,62}{}_{}{}^{}\mathrm{Ni}$, $({\pi }^{-},?)\gamma$ inclusive $\gamma$ ray spectra, $E_{\pi }=0\mathrm{} \mathrm{and} 45$ MeV. Production cross sections for residual nuclei, quasideuteron pion absorption model.

• Received 4 October 1976

DOI:https://doi.org/10.1103/PhysRevC.16.741