EUV-SPECTROSCOPY OF BEAM-FOIL EXCITED 14.25 MEV U XE52+...XE49+-IONS/

14.25 MeV/u Xe - ions with charges q = 52, 51, 50 and 49 were sent thr ough carbon foils of 50-mu-g/cm2. Beam - foil spectra between 6 nm and 14 nm were registered using the GSI 5 m grazing incidence spectromete r. The spectra are dominated by Rydberg transitions from levels with n from 12 to 7. As weak features, 2s - 2p transitions in Li- and Be-lik e ions were observed. Their wavelengths were determined with an accura cy of 0.02 nm using modelled Rydberg lines for the wavelength scale ca libration. Very good agreement with experimental and theoretical resul ts was obtained. The present limitation for the use of Rydberg lines f or an in-situ Doppler shift corrected calibration is emphasized.