Computer Simulation And Design Of Multistage Depressed Collector Of Traveling Wave Tube

Multistage depressed collector of Traveling wave tube is the device used for collecting spent beam according to their speed. The magnetic field of refocusing section can laminarize the spent beam, with different magnetic field presenting different improvement. Multistage depressed collector is an electron optical system, in which spent beam is forced to change its speed under the effect of decelerating field and finally deposits on inner surface, causing huge heat and secondary electron emission.This paper uses simulation software for traveling wave tube to establish the electron optical model for multistage depressed collector. Use this model to combine different magnetic field for refocusing section, change voltage, position and shape of electrode, observe the track of primary and secondary electron, and get numerical result of current and power sedimentation of each electrode and efficiency of collector. With continuous optimizing the structure of collector, a two-stage depressed collector for 8~12GHz, 6.5KW high power traveling wave tube is designed.