摘要:
A device which generates plasma by energizing a column of gas with a high frequency periodic electric field of a frequency of at least 100MHz. The generating means extends over only a part of the gas column and the power of the energizing field is such that the plasma generated includes and extends beyond said part of the gas column. In one embodiment the gas column is contained in an elongated insulating casing and the generating means comprises a first metallic tube open at both ends and surrounding a part of the casing, a second tube enclosing the first, and a connecting ring between the first and second tubes.