Identification of a New Isotope ¹⁸⁶Hf

The new neutron-rich isotope ¹⁸⁶Hf has been produced through a multinucleon transfer reaction by irradiation of natural tungsten targets with 60 MeV/u ¹⁸O projectiles. The ¹⁸⁶Hf activities were separated radiochemically from the tungsten and reaction product mixture. The γ-ray singles spectra were measured with a high resolution HPGe detector. The new isotope 186Hf was identified based on the growth and decay of 737.5keV γ rays from the β^- decay of its daughter ¹⁸⁶Ta. Its half-life has been determined to be 2.6 ± 1.2 min.