Incomplete-fusion reactions have been used to study high-spin states in 171 Tm. Gamma-rays and conversion electrons were measured using pulsed-beam conditions for enhanced isomer sensitivity.A K π = 19/2 + , three-quasiparticle isomer was identified, with a half-life of 1.7(2) µs. The faster than expected transition rates from the isomer can be understood as being due to a chance neardegeneracy, with mixing between the isomeric state and the I π = 19/2 + member of the onequasiparticle rotational band to which it decays. The implied mixing matrix element is 12(2) eV.

Evidence is presented for multiphonon excitations based on a high-spin (25 Planck) intrinsic state in the deformed nucleus 182 Os. Angular momentum generation by this mode competes with collective rotation. The experimental data are compared with tilted-axis cranking calculations, supporting the vibrational interpretation. However, the lower experimental energies provide evidence that more complex interactions of states are playing a role.

No abstract