Excited states in the well-deformed rare earth isotopes 154Sm and 166Er were populated via "safe" Coulomb excitation at the Munich MLL Tandem accelerator. Conversion electrons were registered in a cooled Si(Li) detector in conjunction with a Mini-Orange spectrometer. For the first excited 0+ state in 154Sm at 1099 keV a large value of the monopole strength for the transition to the ground state of ρ2(E0) = 96(42)ṡ10-3 could be extracted. This confirms the interpretation of the lowest excited 0+ state in 154Sm as the collective β-vibrational excitation of the ground state. In 166Er the measured large electric monopole strength of ρ2(E0) = 127(60)ṡ10-3 clearly identifies the 04+ state at 1934 keV to be the β-vibrational excitation of the ground state.
Capture Gamma-ray Spectroscopy and Related Topics
- Pub Date:
- January 2009
- X- and gamma-ray spectroscopy;
- Rare earth metals and alloys;
- Nuclear Experiment
- submitted to Physics Letters B