Filamentary plasma ignited by microwaves in high pressure gases

A filamentary plasma is produced in the microwave cavity filled with argon gases of several atmospheric pressures and is ignited by low power microwaves. It is found that this plasma can be explained by the Schottky's theory of positive columns. The plasma has double structures, i.e. highly ionized part and weakly ionized part, which also is observed by Kapitza's experiments. (auth.)