Measurements of electron density and temperature in a miniature microwave discharge ion thruster using laser Thomson scattering technique

Naoji Yamamoto, Kentaro Tomita, N. Yamasaki, T. Tsuru, T. Ezaki, Y. Kotani, Kiichiro Uchino, H. Nakashima

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

In order to improve the thrust performance of a miniature microwave discharge ion thruster, the relationship between electron number density/temperature and operational conditions, mass flow rate, incident microwave power and magnetic field strength were measured by means of laser Thomson scattering. A photon counting method and a triple grating spectrometer were used against a small Thomson scattering signal and a strong stray laser light. Electron number density increased with incident microwave power and was saturated at critical incident microwave power; it was about 1.2 × 10 18 m-3 at incident microwave power >8 W. In addition, electron number density increased with mass flow rate and became saturated; it was about 1.7 × 1018 m-3 at mass flow rate > 0.04 mg s-1. The electron number density gradually increased with an increase in the number of magnets, i.e. magnetic field strength. There was a sudden jump at thirteen magnets, although the thruster failed to ignite at fourteen magnets. This is because there is an optimum distance between the antenna and the electron cyclotron resonance layer. These results suggest that future improvement in thrust efficiency in miniature microwave discharge ion thrusters may come from the fine adjustment of the magnetic field configuration inside the discharge chamber.

Original languageEnglish
Article number045009
JournalPlasma Sources Science and Technology
Volume19
Issue number4
DOIs
Publication statusPublished - Jun 25 2010

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Thomson scattering
electron energy
microwaves
mass flow rate
lasers
ions
magnets
thrust
field strength
electrons
magnetic field configurations
electron cyclotron resonance
magnetic fields
counting
antennas
chambers
adjusting
gratings
spectrometers
photons

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Cite this

Measurements of electron density and temperature in a miniature microwave discharge ion thruster using laser Thomson scattering technique. / Yamamoto, Naoji; Tomita, Kentaro; Yamasaki, N.; Tsuru, T.; Ezaki, T.; Kotani, Y.; Uchino, Kiichiro; Nakashima, H.

In: Plasma Sources Science and Technology, Vol. 19, No. 4, 045009, 25.06.2010.

Research output: Contribution to journalArticle

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AU - Kotani, Y.

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