Analysis in microwave-driven plasma for miniature space propulsion

Microwave-driven Coaxial Transmission Line Resonator ( µ -CTLR) produces a small-volume high density plasma plume. In the previous study, we discovered that the plasma generated by the µ -CTLR remains stable even at low pressure around tens of mTorr, while consuming minimal power below 10 W (Kim et al 2022 Plasma Sources Sci. Technol. 31 105006). In this study, we have investigated the capability of the µ -CTLR plasma operating at 900 MHz for micro-propulsion applications. At the argon gas flow rate of 100 SCCM (3 mg s −1 ), and the power of 8 W, the plasma plume attains high gas temperature ( > 3000 K), high electron density ( > 10 20 m − 3 ), and electron temperature of about 2 eV. The estimated thrust is about 3.4 mN, demonstrating that the µ -CTLR has high thrust desirable for space micro propulsion systems, together with the other merits of low power consumption and small size.