A summary of recent tests of the theory of Quantum
Electrodynamics in medium-Z ions. Accelerators, Tokamaks, and other
devices are used in these studies.
Tests of QED attempt to measure the Lamb shift in hydrogenic (one-electron) or helium-like (two-electron) transitions. Ions with a few electrons in the inner shells will give X-ray transitions for medium-Z atoms. Small energy shifts of these levels can be predicted by theory and measured experimentally. Tests at the 10-60 part per million level are needed to make critical tests of the QED effects. This field links up to most of the X-ray optics fields in the optics group at the University of Melbourne. (See the introduction for the xray optics home page.)