Wavelength measurement of the1s2sS13−1s2pP23transition in heliumlikeFe24+

Abstract

The wavelength of the transition $1s2s{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}-1s2p{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$ of heliumlike Fe xxv has been measured in beam-foil-excited spectra at 7 MeV/nucleon. The result is $\lambda (2\mathrm{}{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}-2\mathrm{}{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{})=271.02\mathrm{}\mp 0.09$ Å. The present wavelength measurement is sensitive to Lamb-shift contributions alone to a precision of ∓ 3%.