Half-Life and Alpha-Particle Energy of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">U</mml:mi></mml:mrow><mml:mrow><mml:mn>236</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>

Several samples containing ${\mathrm{U}}^{236}$ were examined for measurement of the specific activity and the alpha-particle energy. The samples contained ${\mathrm{U}}^{234}$, ${\mathrm{U}}^{235}$, ${\mathrm{U}}^{236}$, and ${\mathrm{U}}^{238}$, the isotopic composition being known from mass spectrometer data. The samples were "weighed" through fission counting comparison with standards containing known amounts of pure ${\mathrm{U}}^{235}$. The alpha-activity due to ${\mathrm{U}}^{236}$ was determined by ionization chamber energy analysis. The same instrument was used for the energy determination.The half-life of ${\mathrm{U}}^{236}$ was found to be 2.46\ifmmode\times\else\texttimes\fi{}${10}^{7}$ years and the alpha-particle energy 4.499 Mev.