Lifetimes, branching fractions, and oscillator strengths of doubly ionized Tungsten

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