title: A series of tufted carbon fiber cathodes designed for different high power microwave sources.
abstract: We report the fabrication technique of tufted carbon fiber cathodes for different microwave sources. Three carbon fiber cathodes were constructed, including a planar cathode, an annular cathode, and a cylindrical cathode for radial emission. Experimental investigations on these cathodes were performed in a reflex triode virtual cathode oscillator (vircator), a backward wave oscillator (BWO), and a magnetically insulated transmission line oscillator (MILO), respectively. The pulse duration of microwave emission from the reflex triode vircator was lengthened by using the planar carbon fiber cathode. In the BWO with the annular carbon fiber cathode, the uniform electron beam with a kA/cm(2) current density was observed. In addition, carbon fiber has great promise as field emitter for MILOs. These results show that the carbon fiber cathodes can be utilized for electron emission in high power diodes with different structures.
authors.affiliation: College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, PR China.
authors.forename: Lie
authors.initials: L
authors.lastname: Liu
authors.forename: Limin
authors.initials: L
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Zhang
authors.forename: Jianchun
authors.initials: J
authors.lastname: Wen
authors.forename: Yonggui
authors.initials: Y
authors.lastname: Liu