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Title: A miniature electrothermal thruster using microwave-excited microplasmas: Thrust measurement and its comparison with numerical analysis

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.2749336· OSTI ID:20979442
; ;  [1]
  1. Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

A microplasma thruster has been developed, consisting of a cylindrical microplasma source 10 mm long and 1.5 mm in inner diameter and a conical micronozzle 1.0-1.4 mm long with a throat of 0.12-0.2 mm in diameter. The feed or propellant gas employed is Ar at pressures of 10-100 kPa, and the surface-wave-excited plasma is established by 4.0 GHz microwaves at powers of <10 W. The thrust has been measured by a combination of target and pendulum methods, exhibiting the performance improved by discharging the plasma. The thrust obtained is 1.4 mN at an Ar gas flow rate of 60 SCCM (1.8 mg/s) and a microwave power of 6 W, giving a specific impulse of 79 s and a thrust efficiency of 8.7%. The thrust and specific impulse are 0.9 mN and 51 s, respectively, in cold-gas operation. A comparison with numerical analysis indicates that the pressure thrust contributes significantly to the total thrust at low gas flow rates, and that the micronozzle tends to have an isothermal wall rather than an adiabatic.

OSTI ID:
20979442
Journal Information:
Journal of Applied Physics, Vol. 101, Issue 12; Other Information: DOI: 10.1063/1.2749336; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English