Isomeric states in 250Fm and 254No

A preliminary report on the discovery of isomeric states in ²⁵⁰Fm and ²⁵⁴No was included in a recent article on α-emitting isotopes of element 104. The existence and assignments of the 1.8 ± 0.1-sec isomer to ²⁵⁰Fm and the 0.28 ± 0.04-sec isomer to ²⁵⁴No have now been confirmed by cross-bombardment techniques. Isomeric ratios based on measurements of collection efficiency of recoil atoms from the decay of isomeric states are given. An interpretation of the even-even isomers as high-spin two-quasiparticle states is discussed.