AUTHOR=Charles Christine , Boswell Roderick W. , Bish Andrew , Khayms Vadim , Scholz Edwin F. TITLE=Direct Measurement of Axial Momentum Imparted by an Electrothermal Radiofrequency Plasma Micro-Thruster JOURNAL=Frontiers in Physics VOLUME=4 YEAR=2016 URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2016.00019 DOI=10.3389/fphy.2016.00019 ISSN=2296-424X ABSTRACT=

Gas flow heating using radio frequency plasmas offers the possibility of depositing power in the center of the flow rather than on the outside, as is the case with electro-thermal systems where thermal wall losses lower efficiency. Improved systems for space propulsion are one possible application and we have tested a prototype micro-thruster on a thrust balance in vacuum. For these initial tests, a fixed component radio frequency matching network weighing 90 g was closely attached to the thruster in vacuum with the frequency agile radio frequency generator power being delivered via a 50 ohm cable. Without accounting for system losses (estimated at around 50%), for a few 10 s of Watts from the radio frequency generator the specific impulse was tripled to ~48 s and the thrust tripled from 0.8 to 2.4 milli-Newtons.