The energy-level structure of ${\mathrm{La}}^{135}$ has been investigated through the decay of ${\mathrm{Ce}}^{135}$. Conversion-electron and $\gamma$ spectra have been studied using magnetic, scintillation, and solid-state spectrometers. Various $\gamma -\gamma$ and electron-$\gamma$ coincidence experiments have been conducted. A revised level scheme is proposed for ${\mathrm{La}}^{135}$ incorporating a number of new transitions. Spin and parity assignments are discussed.

• Received 12 September 1967

DOI:https://doi.org/10.1103/PhysRev.166.1194