The nuclear level structure of ${\mathrm{Sr}}^{88}$ has been studied through the gamma radiation following the decays of 17.8-minute ${\mathrm{Rb}}^{88}$ and 104-day ${\mathrm{Y}}^{88}$. Gamma rays from ${\mathrm{Rb}}^{88}$ with energies of 0.909±0.004, 1.39, 1.850±0.008, 2.11, 2.68, 3.01, 3.24, 3.52, 3.68, and 4.87 Mev have been resolved and fitted into a level scheme with the assistance of coincidence spectroscopy using cylindrical 3-inch×3-inch NaI(Tl) crystals. The intensity of the ground state beta ray transition from ${\mathrm{Rb}}^{88}$ was determined by comparing the total beta ray activity to the intensity of the 1.85-Mev gamma ray. It was found that 75.9±5.0 percent of the decays are directly to the ground state. From the gamma-ray intensities, the comparative half-lives of all the beta groups could be determined and, thus, parity assignments were made to all the levels. The relative intensities of gamma rays leaving the same level is discussed in relation to single-particle transition probabilities.

• Received 13 July 1955

DOI:https://doi.org/10.1103/PhysRev.101.727