Abstract: | Unreported heavy neutron-rich nuclide 238Th has been produced via a multinucleon transfer reaction by 60MeVIu 180 ions bombardment of natural uranium.Thorium was radiochemically separated from the mixture of uranium and reaction products. 238Pa as a daughter nucleus of 238Th has been identified according to the growth and decay of 238Pa γ rays which has been observed. The half-life of 238Th was determined to be (9.4 + 2.0) min. At the same time, a new γ ray of (89.0 + 0.3) keV with T1/2= (8.9 + 1.5)min was found in the γ spectrum gated with the Kα1, X ray of Pa and assigned to 238Th decay based on the measurements of its transition energy and the half-life. |