Roundabout Klystron Electron Gun Design

Gyro-devices are important sources for millimeter wave and sub-millimeter withthe characteristics of high peak power, high average power, high efficiency andsuitability bandwidth and so on. Especially gyrotron has the superiorities high peakpower and high average power with other apparatus. So gyrotron is vastly applied inmany areas, such as power source of millimeter wave high capability radar, millimeterwave weapons system, millimeter wave communication plasma heating, electroncountermeasure. Especially in later thirty years, gyrotron has been played much respectin America, Russia, England, France, Japan, German and so on. Interiorly, the UESTCHigh Power Microwave Laboratory has studied gyrotron since the late 1970s. At2001, our group leaded has successfully developed the first Ka band third harmonicgyrotron with permanent magnetic field system in the world and reach advanced levelinternationally. Gyrotron electron gun provides the helical ring beam, The beamcharacteristics affect interaction output power and efficiency directly. Combinging withthe prospect of our laboratory, design the small-orbit electron gun and the large-orbitelectron gun, Especially stress the design and study of the large-orbit electron gun.The main works of the dissertation are listed as following:First, know the theoretical basis and software use of EGUN, MAGIC. Representthe theory and calculation method of electron optics.Second, represent the operation principle of the gyrotron electron gun and makethe detailed analyse. Represent the initial design method and optimization means.Third, modulate the small-orbit electron gun and obtain a series of significativeinclusions. Study shows finishing initial design of gun we can optimize the beamperformance by adjusting magnetic field distribution, gun geometry, cathode magneticfield, magnetic field compression ratio, anode voltage and so on.Fourth, set up the model of the large-orbit electron gun, and make theoreticalanalysis and design of the large-orbit electron gun. Due to applying large-orbit electrongun, the velocity spread is lower because of smaller influence of space charge compared with small-orbit electron gun. In the interaction region this beam is easy to startoscillation and reject mode competition effectively.