Observation of Large Orbital Scissors Strength in Actinides
Abstract
The M1-scissors resonance (SR) has been measured for the first time in the quasi-continuum of actinides. Particle-\gamma coincidences are recorded with deuteron and 3He induced reactions on 232Th. An unexpectedly strong integrated strength of BM1 = 11-15 \mu n2 is measured in the E\gamma = 1.0-3.5 MeV region. The increased \gamma-decay probability due to the scissors mode is important for cross-section calculations for future fuel cycles of fast nuclear reactors and may also have impact on stellar nucleosynthesis.