A new linearly extended bifocal microwave plasma device

A new kind of linearly extended plasma source was developed. The prototype of such a device was built up as a barrel with elliptical cross-section. This bifocal shape has two focus lines. A linearly extended microwave antenna is placed along one focus line and the sector of plasma treatment is placed along the second focus line. The antenna is a linear emitter of radial divergent microwave radiation. In this work, a frequency of 2.45 GHz in pulsed and continuous wave (CW) mode was used. The power up to 6 kW CW and 10 kW pulsed is adjustable, pulse on/off times are variable in a wide field. The microwave is reflected by the metallic walls of the barrel and concentrated in the second focus line apart from the antenna. There a quartz tube is placed, that can be evaporated and filled with a working gas at a pressure between 102 and 105 Pa. The presented experiments have been done with Argon up to atmospheric pressure at a gas flow up to 6 slm.