title: Robust, easily shaped, and epoxy-free carbon-fiber-aluminum cathodes for generating high-current electron beams.
abstract: This paper presents the construction of carbon-fiber-aluminum (CFA) cathode by squeezing casting and its applications for generating high-current electron beams to drive high-power microwave sources. The fabrication process avoided using epoxy, a volatile deteriorating the vacuum system. These cathodes had a higher hardness than conventional aluminum, facilitating machining. After surface treatment, carbon fibers became the dominator determining emission property. A multineedle CFA cathode was utilized in a triode virtual cathode oscillator (vircator), powered by a approximately 450 kV, approximately 400 ns pulse. It was found that 300-400 MW, approximately 250 ns microwave was radiated at a dominant frequency of 2.6 GHz. Further, this cathode can endure high-current-density emission without detectable degradation in performance as the pulse shot proceeded, showing the robust nature of carbon fibers as explosive emitters. Overall, this new class of cold cathodes offers a potential prospect of developing high-current electron beam sources.
authors.affiliation: College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, People's Republic of China.
authors.forename: Lie
authors.initials: L
authors.lastname: Liu
authors.forename: Limin
authors.initials: L
authors.lastname: Li
authors.forename: Jianchun
authors.initials: J
authors.lastname: Wen
authors.forename: Hong
authors.initials: H
authors.lastname: Wan