Power discharge cavity, method and device for measuring the air gap breakdown threshold based on the power discharge cavity

Abstract

The invention provides a power discharge cavity, a method and a device for measuring the air gap breakdown threshold based on the power discharge cavity. The method comprises: generating initial electrons on the central surface of a cathode through the focusing of pulse lasers; gradually increasing the laser energy to realize the critical breakdown of the air gap wherein the number of the generated initial electrons is regarded as the air gap breakdown threshold; applying the initial electrons at this time to a voltage condition where the initial electrons do not reproduce themselves and detecting the current generated from their movement; performing the current integration and then, obtaining the number threshold of the initial electrons of the air gap breakdown. According to the method and device for measuring the number threshold of initial electrons of air gap breakdown, it is possible to conveniently and effectively measure the number threshold of initial electrons required by air gap breakdown under the conditions of different gap distances, working coefficients, air pressures and air medium types. Capable of being operated easily, the method and the device can also be used in a wide scope. The method and the device are also be repeatedly used.

Description

technical field [0001] The invention belongs to the field of gas discharge, and in particular relates to a discharge chamber and a method and device for measuring the threshold value of the initial electron number of gas gap breakdown based on the discharge chamber. Background technique [0002] As a device to control current flow and disconnection, the gas gap is widely used in pulse power devices and power systems. The gas switch composed of the gas gap as the basic structure has become an irreplaceable key component in the pulse power drive source because of its strong flow capacity, wide working range, easy control, and long life. The working process of the gas switch includes two stages of static withstand voltage and triggered discharge. In the static withstand voltage stage, the positive and negative poles of the gap are subjected to a DC voltage lower than the self-breakdown voltage. The amplitude is usually determined by the working coefficient, that is, the DC volt...

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Problems solved by technology

Literature (N Sato; S Sakamoto. Undervoltage breakdown between parallel plates inair [J]. Journal of Physics D: Applied Physics, 1979, Vol.12(6), pp.875-885) and literature (Frechette, M.F; Bouchelouh, N; Larocque, R.Y. Laser-induced undervoltage breakdown in atmospheric N 2 correlated with time-resolved avalanches [J]. Proceedings of1994 IEEE International Symposium on Electrical Insulation, 1994, pp.515-517) introduced two measurement methods, both of which generate initial electrons in the gap through the photoelectric effect of the pulsed laser and the electrode , and realized the measurement of the initial number of electrons in the gap breakdown under a certain range of operating coefficients, but there are the following defects: First, the introduction of the laser adopts the axial introduction method, that is, the laser channel penetrates the discharge gap, so that the initial electron movement path The ionization of the gas will affect the development of electrons and affect their current, which will cause errors in the measurement of the number of electrons; secondly, due to opening holes or making mesh structures in the anode, this will cause distortion to the electric field in the gap and cause electric field Inhomogeneity, which in turn affects the motion of initial electrons; third, the laser pulse width used in the literature is on the order of several nanoseconds, so that the initial electrons cannot be regarded as instantaneous emission, and cannot simulate the field emission of initial electrons in the actual gas gap; finally, When measuring the number of electrons, the discharge chamber needs to be evacuated for measurement. Due to the change of the discharge medium, the "inequality" of the experiment will be caused, which will also bring errors to the measurement.

These defects in the measurement methods and procedures, equipment parameters, and experimental device structure design will lead to low accuracy of the measurement results. At the same time, the measurement methods and devices in the literature can only be applied in low air pressure, and cannot be extended to a wider range of applications.

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