Structure of high-spin yrast states in ²⁰⁵Pb and ²⁰⁶Pb

The properties of high-spin states in ²⁰⁵Pb and ²⁰⁶Pb have been investigated using the ²⁰⁴Hg(⁽Be, α4n)²⁰⁵Pb and ²⁰⁴Hg(⁹Be, α3n)²⁰⁶Pb reactions at a bombarding energy of 62 MeV. Decay properties for states up to an excitation energy of 6866 keV and spin of ( 37 2⁺) have been deduced for ²⁰⁵Pb, and up to an excitation energy of 8705 keV and spin of (21⁺) for ²⁰⁶Pb. The level schemes are compared with predictions of multi-particle shell-model calculations. The observation that the yrast 33 2⁺ isomer in ²⁰⁵Pb is essentially bypassed is explained as a consequence of the absence of related configurations of higher spin near the yrast line.