The FERRUM project: new experimental and theoretical f-values for 4p-4d transitions in FeII applied to HST spectra of chi Lupi

Radiative lifetimes for six highly excited levels in Fe II have been measur ed at Lund Laser Centre applying the laser induced fluorescence technique a nd two-step excitation. The energy levels belong to the even-parity 3d(6)(D -5)(4)d subconfiguration at about 10 eV. Branching fractions (BF:s) of 29 t ransitions from these levels to the 3d(6)(D-5)4p subconfiguration at about 5 eV have been measured in the wavelength region 2000-3000 Angstrom with th e Lund Fourier Transform Spectrometer. By normalizing the BF:s with the lif etimes we get experimental oscillator strengths for these 29 4p-4d lines. T he oscillator strengths are compared with new theoretical calculations usin g the orthogonal operator technique and applied to high-resolution spectra of the star chi Lupi, recorded with the Hubble Space Telescope.