Beam-foil spectroscopy of n=3 to n=2 transitions in highly stripped bismuth

The n=3 to 2 transitions in Ne-like, Na-like, and Mg-like bismuth were measured on the UNILAC accelerator at the Gesellschaft f̈r Schwerionenforschung in Darmstadt, West Germany, using the Lawrence Livermore National Laboratory high-resolution double-crystal spectrometer. The measurements cover the region 10 14 keV with precisions of the order of 100 ppm and include electric-dipole and quadrupole transitions. Theoretical multiconfigurational Dirac-Fock calculations were made for the Ne-like system and compared to the experiment. The data exhibit energy shifts of 1.5 2.5 eV from the theory, confirming trends previously observed in tokamak experiments. The Na-like and Mg-like results are compared with unresolved transition array calculations.