Decay ofU240and 7.3-minNp240

The radiations of ${\mathrm{U}}^{240}$ and 7.3-min ${\mathrm{Np}}^{240}$ have been studied with a solenoidal beta spectrometer, beta-and gamma-scintillation spectrometers, and 180° permanent-magnet spectrographs. The principal decay branch of ${\mathrm{U}}^{240}$ is a 0.36-Mev beta transition to the 7.3-min state of ${\mathrm{Np}}^{240}$. The only other radiations observed which are attributed to ${\mathrm{U}}^{240}$ are the conversion lines associated with a 0.044-Mev transition.