Abstract
The final result of a 2s 2p Lamb-shift measurement by the laser resonance method in hydrogenic phosphorus is reported. Metastable 2s ions were prepared using a β≊0.08 velocity beam of ions obtained from the MP tandem accelerator at the Centre de Recherches Nucléaires in Strasbourg. From the metastable state the transition to the 2p state was induced with a high-power dye laser leading to a measured transition energy of ΔE=2.231 33(12) eV. Subtracting the well-known fine-structure splitting Δ=2.314 82(2) eV, the Lamb shift is deduced to be (LS)=20 188(29) GHz. This result is compared with the theoretical value (LS)=20 254(10) GHz and with other experimental results for the Lamb shift in the region Z≤18. Finally, the utility of the Lamb-shift measurements in testing the G(Zα) function of the self-energy, which includes only terms in (Zα, n≥6, is discussed.
- Received 2 April 1993
DOI:https://doi.org/10.1103/PhysRevA.48.1875
©1993 American Physical Society