Lifetimes, branching fractions, and oscillator strengths of doubly ionizedTungsten

A first small set of W III oscillator strengths has been obtained from comb ined lifetime and branching fraction measurements. The branching fractions in the wavelength region of 154-334 nm were measured with a Penning dischar ge and a Fourier transform spectrometer. Three levels have been calibrated on absolute scales with lifetimes measured with the time-resolved laser-ind uced fluorescence technique. The f-values derived have uncertainties of abo ut 8% at best. A comparison with Cowan-code calculations is given since no other data are available in the literature.