Radiations From Tantalum (182), Antimony (122), and Indium (116)

The 100-day activity was induced in tantalum irradiated by slow neutrons in the Clinton pile. The beta-rays of this isotope were found to have a range in aluminum of 0.112 g/${\mathrm{cm}}^2$, and the gamma-rays a maximum energy of 1.16±0.1 Mev as determined by coincidence absorption. The beta-gamma coincidence rate was 0.93×${10}^{-3\mathrm{}}$ coincidence per beta-ray, independent of the beta-ray energy, and a gamma-gamma coincidence rate of (0.27±0.03)×${10}^{-3\mathrm{}}$ coincidence per gamma-ray was obtained. These data indicate that beta-emission by ${\mathrm{Ta}}^{182}$ leads to an exited state of ${\mathrm{W}}^{182}$ and that de-excitation occurs with the emission of two or more gamma-rays in cascade.