Study Of Problems Related Secondary Electrons Of High Power Collector

In the field of military and national defense,the Gyrotron Traveling Wave Tube(Gyro-TWT)meets requirements of high frequency band,high power,high gain,wide band and other characteristics,which has attracted the attention of military researchers from all over the world.In addition to the above characteristics,security is also an important aspect.The collecter is an important part of Gyro-TWT.Inside the collector,disorder of high-energy electron bombardment to scrap collector wall,will be on the surface of the lining material in secondary electron excitation.The secondary electron has great randomness,among which there may be secondary electrons moving far away bombarding the output window at the back end of collector,and secondary electrons moving towards the high frequency region under special conditions backflow into the high frequency structure,damaging the microwave signal output and the vacuum environment of the whole tube,resulting in the whole tube can not work normally.In order to solve the problems related to the secondary electrons in the collector of Gyro-TWT mentioned above,this paper studies the method of suppressing the secondary electrons with the millimeter scale similar supersurface structure.The main research contents and innovation points are as follows:1.Contrast of inhibitory structures.Based on the results published by the authority,a curve of secondary electron emission coefficient of copper material is fitted.In a vertical wall,square hole and similar inhibition on the surface of the super structure,based on the proposed a folding wall structure inhibition,studying the characteristics of higher folding Angle,the size of the cycle,wall wall structures of folding inhibit the effects of the secondary electron will be folded wall structures compared with vertical wall,the structure of the square hole,the results show that under the condition of the simulation,The folding wall structure has a 5% advantage over the vertical wall structure with the best inhibition effect.2.Cylindrical collector electrode study.In the collector of circular TWT,it is found that there are secondary electrons backflow and superdistant transmission phenomena under the electron incident without standing wave interaction.In order to suppress the secondary electrons in the collector,the effect of deflection magnetic field technology was studied.The method of adding the vertical wall structure inside the collector was studied,explore the inhibition effect of different parameters,the research from the aspects of microwave transmission and power capacity of vertical wall structures.The influence of the final result for the secondary electron movement range from 900 mm to580 mm,the ratio of reflux electrons is reduced by about 50%,microwave signal to normal transport.The collector wit the vertical wall can meet the power capacity under a certain duty cycle.The vertical wall structure can effectively suppress the secondary electrons in the cylindrical collector of the Ku-band Gyro-TWT,and the feasibility of this structure is verified.