title: Development and research of a coaxial microwave plasma thruster.
abstract: An overview of the research on a coaxial microwave plasma thruster at Northwestern Polytechnic University is presented. Emphasis is put on the development and research on key components of the thruster system, a microthrust balance, plasma plume diagnostics, and a numerical simulation of the plasma flow field inside the thruster cavity. The developed thruster cavity is chosen from a coaxial resonant cavity with concentrated capacitance, which can operate well in atmosphere and vacuum conditions. The development of a microwave source shows that a magnetron powered by a switch power supply has advantages in the power level and efficiency, but a solid state microwave source synthesized from the arsenide field effect transistor is superior in weight and volume. Through elimination of the effect of large gravity and resistance force induced by a gas pipe line and a microwave transmitting line on the microthrust, 15 mN and 340 s in the performance of the microwave plasma thruster at 70 W and with helium gas are measured. Diagnosing experiment shows that the plasma plume density is in the range of (1-7.2)x10(16)m(3). Numerical simulation of the plasma flow field inside the coaxial thruster cavity shows that there is a good match between the microwave power and gas flow rate.
authors.affiliation: College of Astronautics, Northwestern Polytechnic University, Xi'an 710072, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yang
authors.forename: Yingqiao
authors.initials: Y
authors.lastname: Xu
authors.forename: Jinlan
authors.initials: J
authors.lastname: Tang
authors.forename: Genwang
authors.initials: G
authors.lastname: Mao
authors.forename: Tielian
authors.initials: T
authors.lastname: Yang
authors.forename: Xiaoquen
authors.initials: X
authors.lastname: Tan