Laser Spectroscopy of Highly-Charged Ions

Our Measurements

Measurements we have completed so far include the intercombination intervals (between singlets and triplets), and the J = 0 – 1 or 1 – 2 fine-structure intervals in the n=2 manifold of helium-like nitrogen, fluorine, magnesium and silicon. In all cases the precision of these measurements exceeds that of current theory. Further measurements are being planned for the J = 0 – 2 fine-structure intervals where the theory is more accurate. Comparison between our measurements and theory for helium-like ions enables higher-order QED corrections to the fine-structure of neutral helium to be estimated. This improves the precision of the value of the fine-structure constant that can be extracted.