Design Of Electron Gun For Short Millimeter Wave-band Injection Device

With the development of military technology and the continuous improvement of civilian demand,the vacuum electronic deviceshave higher requirements.Higher frequency,higher power,wider band and miniaturization of the device requirements has brought new challenges to the traditional vacuum electronic devices.Since the small space-charge forceand wide edge of the sheet beam,it has a largeoperating current.So,the sheetbeam is more suitable for producing high-frequency,high-power radiation than the conventional cylindrical beam.And the slow-wave structure of the sheet beam can be used in a flat plate which is more favorable for processing.The development of sheet beam devices will promote the advancement of the vacuum electronic devices.Hence,this paper has carried on the preliminary research on the sheet beam electron gun,and the main work is as follows:1.According to the teaching and research project for the W-band traveling wave tube parameters required to design a work in the W-band single anode sheetelectron gun,the anode operating voltage of 21.1kV,you can get 400 mA stable current,then the cathode surface current density of 28.78A/cm2,the current density is about 133A/cm2.And the gun has a range of about 10 mm,the aspect ratio is 10:3,the size of the beam cross-section is less than 1mm×0.3mm,and the influence of the change of the anode voltage and the change of the anode and the anode distance on the performance of the electron gun is further studied.2.According to the teaching and research project for the 140 GHz backward-wavetube design requirements of a work in the 140 GHz double anode sheet electron gun,the first level of voltage 15 kVthesecond,anode voltage range of work15kV-18 kV,can obtain a stable current of about 42 m A.Here,the cathode emission surface current density of about 14.4A/cm2.The gun has a range of more than 11 mm,the aspect ratio is 10:1,and the beam cross-section size is less than 1mm×0.1mm.The influence of the change of the first anode voltage and the change of the anode and cathode distance on the performance of the electron gun is further studied.3.According to the teaching and research project for the 220 GHz backward-wavetube parameters required to design a work in the 220 GHz double anode sheet electron gun,the first level of voltage 10 kVthesecond,anode voltage range ofwork 8kV-12 kV,can get a stable current of about 18.4mA,The cathode emission surface current density of about 7.5A/cm2,the current density is about 116A/cm2.The gun has a range of more than 7mm,the aspect ratio is 20: 3,and the beam cross-section size is less than 400?m × 60?m.Based on the study of 140 GHz double anode sheet electron gun,this paper further studies the influence of the change of cathode structure and the change of anode channel on the performance of electron gun.Based on the device's actual demand,this paper designs the single anode and the double anode electron gun,and they meet the requirement of parameter index.This research has great reference value for the design of the sheet beam devices.