Snoek peak of neutron-irradiated Fe-3.48 Ni alloy

The Snoek peak of a neutron-irradiated Fe-3.48% Ni alloy was measured to determine the resolution of interstitial impurity atoms. The internal friction was measured after isothermal annealing on specimens irradiated at 75° ± 10°C to a dose of ∼3.6 × 1019 nvt. The change of the Snoek peak height, which corresponds to the amount of nitrogen in solution, was analyzed upon assuming the applicability of the rate equation. As a result of calculation, the order of the reaction was found to be about 2.6, and the activation energy for resolution of nitrogen atoms about 2.9 eV.