An electrostatic probe system with three-electrode structure

Abstract

The invention discloses an electrostatic probe system with a three-electrode structure. The three-electrode probe unit collects electronic current and ion current, and removes radio frequency noise through a high-voltage radio frequency noise reduction unit; the current after removing radio frequency noise is input to a power amplifier through a sampling resistor The probe loop is formed by the ground terminal of the power amplifier unit; the power amplifier unit amplifies the periodic scanning voltage signal generated by the signal control and data processing unit and loads it to the probe pole of the three-electrode probe unit; the current acquisition unit simultaneously collects the probe The current signals of the pole and the reference pole are first actively eliminated by the power frequency interference suppressor, and then input to the signal control and data processing unit through the isolator to obtain the electron density and electron temperature data. Realize the compensation of radio frequency noise and the active elimination of power frequency noise, and then obtain the volt-ampere characteristic curve with high signal-to-noise ratio, and can realize accurate measurement of plasma electron temperature and electron density with strong radio frequency noise and power frequency interference.

Description

technical field [0001] The invention belongs to the technical field of plasma diagnosis, and in particular relates to an electrostatic probe system with a three-electrode structure. Background technique [0002] Electrostatic probe diagnosis has attracted wide attention due to its simple structure, low cost and various diagnostic parameters. The basic principle of electrostatic probe diagnosis is that a metal needle inserted into the plasma will attract ions and electrons in the plasma under the action of voltage, thereby forming a current. The volt-ampere characteristic curve containing information such as plasma electron density and electron temperature is obtained by measuring the probe voltage and current, and then the key parameters of the plasma such as electron temperature and electron density can be calculated according to the curve combined with probe theory. [0003] The current electrostatic probe system has difficulties in diagnosing the plasma containing radio ...

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Problems solved by technology

[0004] Aiming at the problems existing in the prior art, the object of the present invention is to provide an electrostatic probe system with a three-electrode structure, using a three-electrode probe including a probe pole, a compensation pole and a reference pole, combined with a noise suppression circuit to realize the The suppression of noise in the probe current can obtain a high signal-to-noise ratio volt-ampere characteristic curve, which solves the problem of accurate diagnosis of key plasma parameters with radio frequency noise and power frequency interference

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