Hydrogenic Lamb shift in Ge31 and the fine-structure Lamb shift

Abstract

Using x-ray diffraction and beam-foil spectroscopy, we have determined precise wavelengths for Lyman α1 and Lyman α2 in hydrogenic germanium of 1.166 993 8±33±169 and 1.172 433 6±39± 170 Å. Hydrogenic germanium Ge31+ 1s-2 p32 and 1s-2 p 12 Lamb shifts are measured to be 66 080±237±1121 and 67 169±281±1237 cm-1, respectively. This 14 ppm measurement of the wavelengths thus provides a 1.8% measurement of the 2p-1s Lamb shift and is an improvement by a factor of 3 over previous work. Fitting the full two-dimensional dispersion relation, including Balmer and Lyman series, limits random and systematic correlation of parameters. Dominant systematics are due to diffraction parameters including crys..