Photoexcitation of the high-spin J=8 isomer in 176Yb using 8.5Â MeV end-point energy Bremsstrahlung

Excitation of the 1049.8 keV isomeric state (t1/2=11.4 s, spin difference between ground and isomeric states ΔJ=8) in 176Yb using Bremsstrahlung radiation is observed for the first time. In contrast to the photoexcitation of isomeric states in other nuclei with lower spin differences, where effective integrated cross-sections are of order tens to hundreds of barn eV, an integrated cross-section of just 0.0484±0.066 barn eV is observed for 176Yb.