Accurate measurements of 1s2s³S-1s2p³P transition wavelengths of helium-like ions in Tokamak plasmas

Abstract

Reports new measurements of the wavelengths of the 1s2s 3S-1s2p 3P transitions in the helium-like ions of oxygen and fluorine, using a Tokamak as a light source. Results are compared with theory and it is shown that the author's results, and most of the experimental results of other groups for these transition wavelengths in helium-like ions with Z<or=10, may be brought into agreement with theoretical values if a small semi-empirical correction is applied. Possible implications of this for the theory of two-electron ions are discussed briefly.