Research And Design Of 170GHz High Power Gyrotron Electron Optical System

With the development of microwave technology,different kinds of microwave electric vacuum devices have appeared.Among them,the gyrotron is a high-power microwave device.Compared with ordinary microwave devices,it can work at a higher frequency and can output higher power,which has been widely valued by scientific researchers in various countries.The extensive application of the gyroscope promotes its continuous development,and people have higher requirements on the performance parameters of the gyroscope.As the source of the gyrotron,whether the electron gun can produce high-quality electron beams will greatly affect the performance of the gyrotron,which also promotes the development of the electron gun.The magnetron injection electron gun is a kind of electron gun commonly used in gyrotrons at present,it can produce a larger electron beam horizontal and vertical speed ratio and smaller speed dispersion.When the gyroscope works normally,the surface temperature of the cathode emission band needs to reach the temperature required for electron emission to start emitting electrons,and the cathode of the electron gun will be thermally deformed to a certain extent,which will affect the performance of the gyroscope.Moreover,the temperature difference of the surface of the cathode emission band is too large,and the temperature distribution is not uniform,which will affect the emission state of the electron beam.Therefore,after designing a magnetron injection electron gun,it is necessary to perform thermal analysis on it and determine whether the deformation amount has an effect on the performance parameters of the entire tube.The main contents of this article are as follows:1.Introduce the basic theory of electron optical system and the theory of gyrotron electron optics in detail,and explain the related heat transfer knowledge and the specific process of thermal analysis;through the above theory,make further research on the design method and principle of magnetron injection electron gun analysis.2.Two types of particle simulation software were used to optimize the designed magnetron injection electron gun.Several factors affecting the performance of the electron injection were analyzed.A 170 GHz magnetron injection electron gun was designed to make the electron injection speed ratio 1.3.The center radius of the guide is 7.6mm,and the lateral velocity dispersion is 6%,which meets the performance requirements of the gyroscope.3.In order to make the overall structure more compact and meet the requirements of the new magnet structure with a smaller temperature hole,according to the main performance parameters of the previously designed electron gun,another 170 GHz reverse magnetron injection electron gun was designed,and the cathode and the cathode were replaced.The relative position of the anode and the electron beam quality were improved after optimization,and the lateral velocity dispersion was reduced to 5.5%.4.Thermal analysis of the cathode of the designed magnetron injection electron gun.By optimizing the filament power,the number of filaments and the position of the filament,the temperature distribution of the surface of the cathode emission band is more uniform.Efficiency;In order to verify the correctness of the thermal analysis results,and then use different thermal analysis simulation software to make thermal analysis of the same structure electron gun cathode,the results obtained by the two software are good.