Measurement of the 2sS13–2pP23transition energy in heliumlike krypton

Abstract
We report the first measurement of the 1s2s 3 S1–1s2p 3 P2 transition in heliumlike krypton produced by beam-foil interaction at 34.31 MeV/amu. Measurement is sensitive to higher-order relativistic contributions and to quantum electrodynamic effects. The accuracy corresponds to about 5% of the Lamb shift.