States in Odd-OddTl200Populated by the Electron-Capture Decay ofPb200

Low-spin states in ${\mathrm{Tl}}^{200}$ have been studied via the decay of 21.5-h ${\mathrm{Pb}}^{200}$, which was prepared by the reactions, ${\mathrm{Tl}}^{203}(p, 4n){\mathrm{Pb}}^{200}$, ${\mathrm{Hg}}^{202}(\tau , 5n){\mathrm{Pb}}^{200}$, and ${\mathrm{Tl}}^{203}(\tau , 6n){\mathrm{Bi}}^{200}\to {\mathrm{Pb}}^{200}$. Its $\gamma$ rays were studied in singles, coincidence, anticoincidence, and Ge(Li)-Ge(Li) two-dimensional (2048 × 2048 channel) coincidence experiments. Nineteen $\gamma$ transitions have been assigned to the decay of ${\mathrm{Pb}}^{200}$, and all have been placed in a consistent level scheme, States in ${\mathrm{Tl}}^{200}$ populated by ${\mathrm{Pb}}^{200}$ decay lie at 0 ($I\pi =2-$), 147.63 (0-), 257.19 (1-), 289.24 (2-, 1-) 289.92 (1-), 450.56 (1-), 525.54 (1-), and 605.44 keV (1-). Our spin and parity assignments are based on measured conversion coefficients, relative photon intensities, and $log\mathrm{ft}$ values. The structures of the states are discussed in terms of the coupling of the possible single-particle states in adjacent odd-$A$ nuclei. We also place an upper limit of 1 sec on the half-life of any possible isomeric state in ${\mathrm{Pb}}^{200}$ itself.