Design Of Collector For High Average Power Gyro-TWT

Millimeter wave plays an important role in radar,electronic confrontation and communication because of his own characteristics.As a signal amplifier with fast wave structure,the Gyro-Travelling wave tube(Gyro-TWT)has the characteristics of wide working band,high output power and high gain,which becomes the most important research field in high power millimeter wave technology.At the entrance of the Gyro-TWT collector,after the energy exchange with the microwave,the electron beam continue to do axial movement.In the axial decreasing magnetic field,the electron beam with certain energy is moving to the inner wall of the collector,and the residual energy of electron is converted into heat energy,which is taken away in time by cooling water.If the electrons collecting area is too concentrated,it will result in a high temperature rise.Excessive temperature rise will bring pressure to the heat dissipation and affect the working environment inside the tube.It is crucial of collector design to improve the efficiency of collecting and raise the collecting uniformity of the spent electrons.This paper including:1.In order to determine the unit area power capacity and enhance the power capacity of the collector,by means of theoretical analysis,the maximum electric field distribution is obtained.The relationship between the breakdown voltage with the vacuum degree of the tube,the vacuum degree with the dissipation power of the collector,and the collector maximum temperature with the dissipation power is obtained by means of software simulation and experimental data.The liquid cooling efficiency is improved by increasing the heat conduction coefficient,liquid cooling water velocity and improving liquid cooling structure of the collector,and the helix-wave micro-channel collector is simulated and analyzed.When the dissipation density is 1.65 kW/cm~2,the highest temperature of collector and cooling water are both lower than the respective temperature threshold,and the maximum dissipation power can be effectively collected.2.In order to improve the collecting uniformity of electron beam,the electron beam phase function in the collecting area is used to describe the electron beam distribution,and the program of collection density is compiled using MATLAB.For a single state electron beam under uniform magnetic field,the problem of collecting area and collecting uniformity are studied in the case of linear collector,equal slope gradient collector and variable slope gradient collector,and the"spike"of the collection density is effectively solved by means of variable slope curve collector,which makes the collecting of the dissipative electron beam more uniform.3.Aiming at the problem of the layered electron beam under the uniform magnetic field,the collecting density is studied under the diagonal collector,the relationship between the collecting shape and the collector angle and the electron cyclotron angle is obtained,and the problem of collecting"burr"appearing in the programming calculation is analyzed.As for the problem of collecting the layered electron beam under the gradient magnetic field,the collecting uniformity is improved by the way of increasing the compensation coil in the collector region by comparing the collecting density with the uniform magnetic field.Using CST software to analysis,the collector has better microwave transmission characteristic after adding compensation coil.