Hybrid disorder carbon fiber cathode for high current pulsed electron beam emission

Abstract

Cathode plays a paramount function in high current pulsed electron beam (HCPEB). Herein, a novel design of cathode with hybrid short carbon fiber (SCF) and carbon fiber powder (CFP) was developed. The surface morphology of cathode with varied CFP additions was characterized by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and atomic force microscope (AFM). Electrical property and electron beam emission property of different cathodes were investigated. Results revealed that the microstructure of the cathode presented disorder contact structure, the conductive network became denser and the micro-protrusions on the cathode surface were remarkably increased through the moderate addition of CFP. Notably, the cathode by adding 1.5 vol% of CFP manifested the least electrical resistance 1.2 Ω and showed the best electron beam emission performance with beam spot diameter 50 mm at a plateau duration 1.6 μs. Moreover, there was no obvious damage occurred on the surface of cathode (1.5 vol%) after 1000 electron beam emission, which exhibited long lifetime. This study provided an insight for the development of HCPEB cathode.