Study Of Carbon Fiber Cathodes Used In Repetition Rate And Intense Current Electron Beam Diodes

Repetition rate and intense current electron beam diode was a critical part of repetition rate high power microwave system. The emission of repetition rate and intense current electron beam has different character with single pulse emission, and it has different request to the cathode. Carbon fiber cathode is a kinds of widely used and researched cathodes. It has very well emission peculiarity. Analysis of the feature of the repetition rate and intense current diode and research of the carbon fiber used in repetition rate and intense current diode have profound meaning to the development of technic of high power microwave.This paper firstily analysed the feature of the repetition rate diode, especially analysed the process of the recombination of the charged particle in the plasma. The results of the analyses indicated that the process of the iron and the negative iron which created by the particle absorb the electron was the main mode of recombination on the condition that the density of plasma was decreased in a large scale. The charged partical density is decrease in exponential relationship with the time. We concluded that the repetition rate diode required the cathod preduce low tempreture and low density plasma; has long lifetime; starting fast, has low outgassing rate, uniformly emission electron beam.Based on the basic theory of the emission of electron and require of the repetition rate diode, we analysed the character of the carbon fiber's emission. We find that the carbon fiber cathode preduce low tempreture and low density plasma; has long lifetime; starting fast, uniformly emission electron beam. It fit the demand of the repetition rate diode very well.Based on the structure of the diode, we made a carbon fiber cathode and did some experimental investigation of the carbon fibe cathode used in the repetition rate diode. We measured the electron beam current and the votage of the diode on condition that the repetition rate was 100Hz. The electron beam current is 1.96kA, and the votage of the diode is about 350kV. It shows that the electron beam current and the votage of the diode are very stable, and hve very good repetition characteristic.Finally this paper summarizes the works we have done before and also proposes the new ideas and plans in the future investigations.