Resonance probe

• Ikegami H.

  Research Information Center, Institute of Plasma Physice, Nagoya University

• Takayama K.

  Research Information Center, Institute of Plasma Physice, Nagoya University

抄録

The resonance probe method is a new technique developed by the authors to determine density, temperature and effective collision frequency, of electrons in an instant. The frequency of a low-voltage rf signal superposed on a probe is swept within an adequate frequency range and the dc component of the electron : current due to the nonlinearity of the sheath impedance is measured. It has been found that resonant increase appears in the current at the electron plasma frequency. The characteristic curve of the resonance probe consists of the following three frequency ranges : The first lower frequency range where the electron current keeps a constant value independent of the frequency, the second range where a resonance peak appears, and the third higher frequency range where the superposed rf signal brings no dc current increase. It is quite noticeable that the resonant increase in the second range appears at the electron plasma frequency. For a partially ionized plasma, the resonance peak height δj_r and the half-width Δω_1/2 are given by the following formulae, δj_r = j_o 1/(√<2>)(ω_p)/ν(λ_D)/L (eδV)/(κT)√<(eV)/(κT) I_1 ((eδV)/(κT), Δω_<1/2>=2ν, where T is the electron temperature, ω_p is the electron plasma frequency, λ_D is the Debye length, j_o is the electron current density to the probe when no oscillating field is superposed on it, δV is the amplitude of the superposed rf voltage, I_1(Z) is the modified Bessel function of the first order, L is a distance across which the extenal rf electric field is applied, V is the potential difference between the plasma and the probe, and νis the effective collision frequency of the electron with neutral molecules. the electron temperature is readily given by the increase in the first lower frequency range, δj = j_o {I_o ((eδV)/(κT)) - 1}, where I_o(Z) is the modified Bessel function of the zeroth order. In this paper, some experimental procedure, theory and application of the resonance probe are described in detail.

収録刊行物

• Research report

  Research report 10 1-31, 1963-03

  核融合科学研究所

詳細情報

• CRID: 1570291226922807040
• NII論文ID: 110001025722
• NII書誌ID: AA0081640X
• ISSN: 04694732
• 本文言語コード: en
• データソース種別:
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