Results of experimental and theoretical investigations of a homogeneous discharge in SF$-6$/ gas have been presented. Experiments with use of electrodes made of Al have clarified that even by small current densities (below 20 A/cm$+2$/) and pulse durations (50 ns) the cathode surface is covered by a number of hot spots, which influence discharge homogeneity and stability. The hot spot density of about 10 cm$+$MIN@2$/ is found to be necessary for ignition of a homogeneous discharge. In order to achieve desirable hot spot density special kinds of cathodes with predefined hot spot number have been designed. These cathodes have provided high discharge homogeneity and stability.
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