Abstract: In the present application there is disclosed an improvement in the operation of transverse energization systems for atmospheric pressure CO.sub.2 lasers using a plasma forming plate in which a subsidiary or auxiliary spark gap is provided between one end of the cathode bus bar and the plasma forming plate. Most of the current for the main discharge thus passes through this subsidiary spark gap, and small glow discharges rather than arcs occur between the tips of the cathode pins and the edges of the holes in the plasma forming plate. The use of elongated slots in the plasma forming plate and the use of a mesh in place of the discrete slots is also disclosed. The results of experiments conducted utilizing apparatus of the prior art and of the present invention are also included.