Radiative lifetimes of excited W I levels

Time-resolved laser-induced fluorescence spectroscopy has been used to measure the lifetimes of 47 selected W I levels with energies between 27800 and 48200 cm(-1). A high-current hollow cathode produces an effusive beam of tungsten atoms and ions in the ground states and in metastable states. Selected states are populated with tunable dye laser pulses. The subsequent fluorescence is measured by means of a Tektronix 1 GHz transient digitizer. By taking into account the separately measured response function of the system the lifetimes can be determined from the full decay curve. All measurements are performed with linearly polarized laser beams adjusted to the magic angle in order to exclude systematic error sources. The decay curves also have been inspected for quantum beats and for saturation effects. A comparison with the scarce literature data is given.