The Half-Life ofAm243

The alpha half-life of ${\mathrm{Am}}^{243}$ was found to be 8800±600 years. The ratio of ${\mathrm{Am}}^{243}$ and ${\mathrm{Am}}^{241}$ masses in the sample was measured with a mass spectrometer, and the ratio of their alpha activities was measured with a differential alpha pulse analyzer. A method for preparation of thin samples of americium by electrodeposition is described.