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Title: Means to remove electrode contamination effect of Langmuir probe measurement in space

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.4722167· OSTI ID:22072315
; ; ;  [1]
  1. Plasma and Space Science Center, National Cheng Kung University, No.1 Ta-Hsueh Rd., Tainan 70101, Taiwan (China)

Precaution to remove the serious effect of electrode contamination in Langmuir probe experiments has not been taken in many space measurements because the effect is either not understood or ignored. We stress here that one should pay extra attention to the electrode contamination effect to get accurate and reliable plasma measurements so that the long time effort for sounding rocket/satellite missions does not end in vain or becomes less fruitful. In this paper, we describe two main features of voltage-current characteristic curves associated with the contaminated Langmuir probe, which are predicted from the equivalent circuit model, which we proposed in 1970's. We then show that fast sweeping dc Langmuir probes can give reliable results in the steady state regime. The fast sweeping probe can also give reliable results in transient situations such as satellite moves through plasma bubble in the ionosphere where the electron density drastically changes. This fact was first confirmed in our laboratory experiment.

OSTI ID:
22072315
Journal Information:
Review of Scientific Instruments, Vol. 83, Issue 5; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
Country of Publication:
United States
Language:
English