Measurement of xenon plasma properties in an ion thruster using laser Thomson scattering technique

作者：Yamamoto N^*; Tomita K; Sugita K; Kurita T; Nakashima H; Uchino K

来源：Review of Scientific Instruments, 2012, 83(7): 073106.

DOI：10.1063/1.4737144

This paper reports on the development of a method for measuring xenon plasma properties using the laser Thomson scattering technique, for application to ion engine system design. The thresholds of photo-ionization of xenon plasma were investigated and the number density of metastable atoms, which are photo-ionized by a probe laser, was measured using laser absorption spectroscopy, for several conditions. The measured threshold energy of the probe laser using a plano-convex lens with a focal length of 200 mm was 150 mJ for a xenon mass flow rate of 20 mu g/s and incident microwave power of 6 W; the probe laser energy was therefore set as 80 mJ. Electron number density was found to be (6.2 +/- 0.4) x 10(17) m(-3) and electron temperature was found to be 2.2 +/- 0.4 eV at a xenon mass flow rate of 20 mu g/s and incident microwave power of 6 W. The threshold of the probe laser intensity against photo-ionization in a miniature xenon ion thruster is almost constant for various mass flow rates, since the ratio of population of the metastable atoms to the electron number density is little changed.

• 出版日期2012-7