Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA
Abstract:
We have measured the absolute wavelengths of the fine structure components of the 1s2s2p25P-1s2p35S transition in beryllium-like oxygen using the method of fast ion spectroscopy. These results represent the first measurement of fine structure in any core-excited 4-electron ion. We have also measured the lifetime of the metastable 1s2p35S state. The structure and lifetime results are compared with recent relativistic MCHF calculations.