A large bore fast axial flow CO/sub 2/ laser

A single-tube large-bore fast axial-flow CO/sub 2/ laser with a power output of 3.8 kW using a discharge length of 0.6 m is described which operates at currents in excess of 1.2 A. The high-power compact design is made possible by the use of multiple electrodes and by optimizing gas turbulence using high-velocity gas injection at the anodes to suppress the glow-to-arc transition and to fill the discharge tube. The critical parameters in raising the current at which the glow-to-arc transition occurs are shown to be the number and surface area of the cathodes and the effectiveness of the gas turbulence over the discharge length. The importance of the transition regions between the column and the electrodes is shown. Operation at currents in excess of 2 A without a glow-to-arc transition has been achieved.<>