Output and threshold characteristics of small-bore pulsed xenon ion lasers are presented in detail as a function of current and gas pressure for ranges of these parameters that are consistent with high optical power output in the green-blue spectral region. It has been found that six wavelengths characteristic of xenon exhibit peak output powers greater than 100 watts, from a 5-foot laser tube over a limited (8-24 mtorr) range of xenon tube pressure. Laser action has also been obtained at high peak powers for longer current pulse (

s) operation of the tube. In addition, observation of three new laser wavelengths 5340, 5501, and 5590 Å is reported. These lines are only observed at very low tube pressures and very high peak currents.