The decay of ${\mathrm{Th}}^{234}$(U${\mathrm{X}}_1$) and ${\mathrm{Pa}}^{234}$(U${\mathrm{X}}_2$ and UZ) has been investigated by means of a coincidence scintillation spectrometer. Three gamma rays at 29, 63, and 92 kev were found in U${\mathrm{X}}_1$. Four gamma rays at 250, 750, 1000, and 1810 kev were found in U${\mathrm{X}}_2$, and four gamma rays at 250, 760, 910, and 1680 kev were observed in UZ. The coincidence relations between the gamma rays, and also between the gamma rays and the beta radiation, have been investigated. A decay scheme is proposed and spin and parity assignments have been made for some of the levels of ${\mathrm{Pa}}^{234}$ and ${\mathrm{U}}^{234}$.

• Received 31 March 1954

DOI:https://doi.org/10.1103/PhysRev.96.1075