A new heavy neutron-rich isotope Th-238

A new nuclide Th-238 has been produced via multinucleon transfer reaction i nduced by 60MeV/u O-18 ion irradiation of natural uranium. The thorium was radiochemically separated from the mixture of uranium and its reaction prod ucts. The activity of thorium was measured by using a HPGe detector and a p lanar HPGe detector. The Th-238 has been identified for the first time by m easuring the growth and decay of the gamma-rays from its daughter Pa-238. T he half-life of Th-238 was determined to be (9.4 +/- 2.0)min. In addition, a new (89.0 +/- 0.3)keV gamma-ray with T-1/2 = (8.9 +/- 1.5)min was observe d and assigned to Th-238 decay based on the measurement of transition energ y and half life.