60MeV/u O-18 ion beam delivered by the Heavy Ion Research Facility in Lanzh
ou (HIRFL) bombarded the natural tungsten targets. The Hf-186 was produced
by multinucleon transfer reactions. The hafnium fraction was separated radi
ochemically from the mixture of tungsten and the reaction products. The gam
ma activity was measured with a HPGe detector. The growth and decay of Ta-1
86 gamma-rays has been observed, which indicates the Hf-186 as a parent of
Ta-186 were produced. The half-life of Hf-186 has been determined to be (2.
6 +/- 1.2)min.