Experimental Diagnosis Of Intermediate Frequency Discharge Of Low Pressure Needle Plate Electrode

Similar to earth,the surface of Mars is shrouded in an atmosphere,but the atmosphere on the surface of Mars is different in composition,pressure and temperature from the earth's surface environment,so the Mars surface rovers have different operating requirements than ordinary equipment on the earth's surface.Various electronic devices of the Mars surface rover will experience drastic environmental changes when they arrive at the surface of Mars and are used,which will lead to rapid deterioration of the performance of electronic components,and even lead to charge accumulation,breakdown and discharge,and burn out the electronic components.At low temperature and low pressure,the breakdown of discharge between electrodes follows Paschen's law,that is,the voltage at the moment of gas breakdown is only related to the product of pressure and electrode spacing.This paper aimed at the surface of Mars probe welding point on the surface of the equipment design different cross-sectional area of needle electrode,through the experiment to observe the needle plate electrode in different working gas(Mars standard gas,helium,nitrogen and carbon dioxide)and under the condition of low intermediate frequency under maintain after discharge breakdown voltage,breakdown voltage and discharge current,and the two-dimensional distribution of plasma emission spectrum.It is found that the breakdown voltage is affected by the gas type,air pressure,the distance between the electrodes and the type of the needles.By analyzing the variation of the maintenance voltage and discharge current after the discharge breakdown of helium,nitrogen,carbon dioxide and Mars standard gas,it is found that when carbon dioxide and Mars standard gas are discharged under low pressure condition,the maintenance voltage and discharge current both appear positive breakdown.Under the condition of high pressure,the breakdown voltage and current appear reverse breakdown.In addition,according to the spatial variation of plasma luminescence intensity after gas breakdown,the phenomenon and forming conditions of gas conversion from glow discharge to arc discharge after gas breakdown are analyzed.Briefly compared the different kinds of gas plasma glow after the breakdown of the differences between two-dimensional emission spectrum image and characteristic,the spatial variation of the luminous intensity of the plasma after the breakdown of these four different types of gases,including helium,nitrogen,carbon dioxide and Mars standard gas,are analyzed,briefly described the carbon dioxide gas when the pressure increases and Mars standard by glow discharge into arc discharge phenomenon.I found that carbon dioxide and Mars standard gas at the pressure of 600 Pa and 900 Pa,with the increase of needle plate spacing,the luminous area of the generated plasma will shrink,the luminous intensity will increase,and from the diffuse glow discharge into arc discharge.At the end of the paper,the effect of the needle electrode shape on the luminescence intensity of the plasma after the breakdown of the standard gas on Mars is briefly introduced.