A single chamber gas discharge laser system having a pulse power source for producing electrical discharges at the rate of at least 1000 pulses per second. The discharge along with laser optics create two short lived gain media, one for producing a seed beam and the other for amplifying the seed beam. Laser gas circulation around a chamber circulation path is provided and the electrodes and discharges are arranged so that debris from one of the gain media is not circulated to the other gain media during discharges until the debris has made a loop around at least 90% of the chamber circulation path.