Characterization of the slot antenna microwave plasma source

An annular ring slot antenna is used as the generation of large-volume 2.45 -GHz microwave plasma. With argon, a surface wave at the quartz tube can be excited above 250 W. Optical emissions testify the existence of azimuthal modes of m = 4 at a pressure of 10 Pa and m = 6 at a pressure of 230 Pa. An important conclusion that the uniformity of electromagnetic field in plasm a has a dependence on the value of plasma density has been acquired based o n theoretical calculations under low pressures. Meanwhile, the efficiency o f the plasma source is investigated experimentally, Especially, the spatial distribution of plasma parameter show that homogeneous plasma cylinder wit h a diameter of 160 mm has been successfully produced at the pressure of 10 -1000 Pa.