Generation of plasma torch by 2.45 GHz microwaves from a solid-state power amplifier

Abstract

High efficiency electrodeless plasma at atmospheric pressure was generated using 2.45 GHz microwaves with a solid state power amplifier (SSPA) to achieve greater plasma efficiency in a type WR340 rectangular resonator, in comparison with magnetron. Plasma flames were sustained in a discharge tube with an inner diameter of 26 mm by swirl flow. With an applied power of 3.3 kW and the injection of 50 lpm swirl air, the plasma flame length of the SSPA was 630 mm, demonstrating an almost 30% increase compared with the magnetron flame length. Subsequently, the Q factors, indicating energy efficiencies of the magnetron and SSPA, were calculated using frequency analysis data. The obtained Q factors demonstrated an increase in plasma efficiency by almost one order of magnitude with the SSPA on the WR340 resonator as compared to the magnetron.