Design of 325 MHz RF grid-controlled high voltage thermionic cathode electron gun
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摘要: 高重复频率、高平均流强的电子枪具有十分广泛的应用。设计了一台束团重复频率为325 MHz在CW模式工作的微波栅控高压型热阴极电子枪,并详细论述了该类型微波栅控电子枪的实验原理。在该类型电子枪的设计中,首先需要利用仿真模拟软件EGUN、POISSON(PoissonSuperfish)、GPT(General Particle Tracer)完成300 kV直流高压电子枪的结构设计,并进行束流动力学验证计算。为将微波馈入该直流电子枪的阴栅极之间,进行了该微波栅控电子枪的供电系统设计,完成了从射频功率源到同轴热阴极的阻抗匹配方案,设计了一种325 MHz双模式同轴供电器件,并进行了验证与分析。Abstract: The electron gun with high repetition rate and high average current has a very wide range of applications. This paper presents the design of a microwave grid-controlled high-voltage thermionic electron gun working in CW mode with a bunch repetition rate of 325 MHz and elaborates the experimental principles of this kind of electron guns. Firstly, simulation software EGUN, POISSON (Poisson Superfish) and GPT (General Particle Tracer) are used to accomplish the structure design of a300kV high-voltage DC electron gun and beam dynamics verification.Secondly, to feed the microwave into the gap between the cathode and the grid of the electron gunefficiently, design of a power supply with a scheme of impedance matching from the radio frequency power source to the cathode is completed.Accordingly, a 325 MHz dual-mode coaxial power supply device is designed, and its feasibility is verified and analyzed..
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表 1 电子枪设计参数
Table 1. Parameters of electron gun
voltage/kV frequency/MHz working mode beam current/mA beam transverse emittance/(mm·mrad) energy spread/% −300 325 CW 5 <5 <0.5 -
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