New neutron-rich nuclide185Hf

Abstract

The unreported hafnium isotope 185Hf has been identified for the first time. Sources of 185Hf prepared by 14-MeV neutron irradiation of tungsten followed by radiochemical separation have been studied. The new activity was identified by following the time variation of the r-rays.The half-life of 185Hf has been determined to be 3.5• 0.6 min. In addition, a new 164.5~O.5keV ~-ray was found and assigned to 185Hf based on the measurements of transition energy and half-life.