Theoretical and experimental study of the microwave cut-off probe for electron density measurements in low-temperature plasmas

Journal Article · Sat Oct 01 04:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3647760· OSTI ID:22036734

Bin, Li; Hong, Li; Huihui, Wang; Jinlin, Xie; Wandong, Liu ^[1]

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1. CAS Key Laboratory of Basic Plasma Physics and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

The microwave cut-off probe for the electron density measurement in low-temperature plasmas is described in this article. It is based on the wave cutoff in an unmagnetized plasma. The measurement principle is analyzed theoretically using a model of plasma slab. Because of the high-pass characteristic of plasma, the waves above the cut-off frequency can penetrate the plasma slab, whereas the lower frequency waves are reflected from the cut-off layer. Therefore, an obvious critical point can be observed in the wave transmission spectrum. The abscissa of the critical point indicates the cut-off frequency, which is directly related to the maximum electron density between transmitting/receiving antennas of the cut-off probe. The measured electron densities are in agreement with the data obtained by the Langmuir probe. Experimental results show that the microwave cut-off probe can be used to diagnose the plasmas with a wide range of parameters.

• OSTI ID: 22036734
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 7 Vol. 110; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANTENNAS
ELECTRON DENSITY
LANGMUIR PROBE
LAYERS
MICROWAVE RADIATION
PLASMA
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA WAVES
REFLECTION