Electron density control system of large-area uniform plasmas

Abstract

The invention discloses an electron density control system of large-area uniform plasmas, and mainly solves the problems in the present plasma electromagnetic wave propagation experimental device that the electron density cannot be continuously adjusted, the long-time stability is poor and the control accuracy is low. The whole system comprises a plasma producing cavity (1), a diagnosis device (2), a power supply device (3), a vacuum device (4) and a control device (5), wherein the control device (5) is used for reading an electron density value measured by the diagnosis device (2), comparing the electron density value with a preset electron density value and outputting a voltage or air pressure control signal according to a comparative difference value; and the output power of the power supply device (3) or a set air pressure value of the vacuum device (4) is adjusted, so as to enable the electron density of the plasmas to be stabilized within a preset value range. The electron density control system has the advantages that by adopting a feedback control principle, the adjustment and the stabilization of the electron density in the large-area uniform plasmas are realized; and the electron density control system can be used for conducting propagation experiments of electromagnetic waves in plasmas with different electron density.

Description

technical field [0001] The invention belongs to the field of gas discharge plasma, and relates to a large-area uniform plasma electron density control device, which can be used for adjusting and stabilizing the electron density in a large-area uniform plasma, and performing electromagnetic waves in plasmas with different electron densities. Spread experiment. Background technique [0002] Studying the propagation characteristics of electromagnetic waves in plasma and the interaction between plasma and electromagnetic waves is the basis and key content of research work such as spacecraft reentry, ionosphere research, and plasma stealth technology. In the theoretical research process, the plasma is generally assumed to be uniform and stable, or the plasma is layered according to the electron density, and the electron density in each layer is uniform and stable. Therefore, controlling the electron density of the plasma to stabilize the set value for a long time is helpful to c...

AI Technical Summary

Problems solved by technology

[0005] 1. The shock tube uses the instantaneous high temperature generated by the high pressure difference to generate plasma, the duration is extremely short, the stability is extremely poor, and it is difficult to control

[0006] 2. Although the plasma produced by the arc wind tunnel and plasma jet can work for a long time, the electron density can be adjusted continuously and is relatively stable, but due to the high temperature in the environment, its electron density is difficult to measure, and the estimation method is generally used OK, the control accuracy is extremely low

[0007] 3. Although the plasma generated by glow discharge has the advantages of easy control, no harsh conditions, and continuous adjustment of electron density, but because it adjusts the electron density value by adjusting the power based on experience, without feedback control, as shown in the attached figure 1 As shown, or only by measuring the voltage between the electrodes, the electron density is deduced, and then the feedback control is performed, and the electron density value of the plasma is not only related to the discharge power and the voltage between the electrodes, but also related to other factors such as the gas temperature and so on. Changing factors are related, so the long-term stability of electron density is poor, and the control accuracy is low

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