Nuclear Structure Physics With A Free Electron Laser

摘要

First Nuclear Resonance Fluorescence (NRF) experiments were performed at the storage ring FEL-driven High Intensity γ-ray Source (HIγS) at the DFELL. Sharp NRF γ-lines were observed from ~(11)B, ~(32)S, ~(88)Sr, and ~(138)Ba nuclei. Azimuthal NRF intensity ratios were measured around the polarized HIγS beam. Electric character was thereby deduced for 18 dipole excitations in ~(138)Ba in the energy range between 5.5 and 6.5 MeV and for two dipole excitations in ~(88)Sr at 4.742 MeV and 7.535 MeV excitation energy. These initial experiments demonstrate the superior performance of the HIγS facility in making such measurements.