Nuclear Resonance Fluorescence inKr82

Abstract

The 777-keV excited state of ${\mathrm{Kr}}^{82}$ has been investigated by means of nuclear resonance-fluorescence scattering experiments. The level width was found to be (9.6±1.5)×${10}^{-5\mathrm{}}$ eV, corresponding to a mean life of (6.9±1.1)×${10}^{-12\mathrm{}}$ sec. From this result and the relative reduced transition probabilities determined previously by Heydenberg, Pieper and Anderson, the mean lives for first excited states of other even-even Kr isotopes can be obtained. No resonant scattering from the 1.475-MeV state of ${\mathrm{Kr}}^{82}$ was observed and its mean life was estimated to be >1.2×${10}^{-12\mathrm{}}$ sec.