The studies on large aperture volume discharge of TEA (transversely excited atmospheric) CO<sub>2</sub> laser are reported. To
obtain stable and uniform large aperture volume discharge, the effects of electrode profiles, preionization methods and
parameters of discharge circuit have been studied experimentally. For a discharge construction with 70 mm gap and
pumped by a 3-stage Marx high voltage pulse generator circuit isolated by resistance with 0.5 μF capacitance each stage,
150 J pulse energy was obtained from a discharge volume about 4 l.