New IsotopeAu204and Decay ofAu202

Irradiation of ${\mathrm{Hg}}^{204}$ with 14.8-MeV neutrons was found to produce a new radioactive nuclide which was assigned to ${\mathrm{Au}}^{204}$ produced through the ${\mathrm{Hg}}^{204}(n, p){\mathrm{Au}}^{204}$ reaction. The following radiation characteristics have been observed to belong to the decay of ${\mathrm{Au}}^{204}$: half-life, 4.0±1.0 sec; $\beta$ endpoint energy 4.5±0.3 MeV; $\gamma$-ray energy 0.43±0.01 MeV. ${\mathrm{Au}}^{202}$ was produced through the reactions ${\mathrm{Hg}}^{202}(n, p){\mathrm{Au}}^{202}$ and ${\mathrm{Tl}}^{205}(n, \alpha ){\mathrm{Au}}^{202}$. The half-life of this nuclide was determined to be 30±3 sec. The $\beta$ endpoint energy of 3.5±0.2 MeV and $\gamma$ rays of 0.44±0.01 and 0.52±0.02 MeV were observed to belong to the decay of ${\mathrm{Au}}^{202}$. The relative intensities of $\gamma$ rays were measured to be 100 and 2.5±1, respectively.