Preparation of a miniature carbon nanotube paste emitter for very high resolution X-ray imaging

A miniature carbon nanotube (CNT) paste emitter dot with a diameter of similar to 50 mu m was fabricated onto the cross-sectional surface of Kovar (nickel-cobalt ferrous alloy) rod without using a sophisticated photolithography. A highly adhesive CNT paste was prepared with silicon carbide and nickel nanoparticles, and then the small CNT emitter was fabricated by a novel and facile technique, called point contact method. The prepared emitter generates very high current density of similar to 11.2 A/cm(2) when measured using a diode configuration. We further observed for the first time the brightness of electron beam generated from the CNT paste emitter that is a more practical point electron source than the individual CNT emitter. The triode structure fabricated with a miniature CNT paste emitter and a gate aperture (20 mm in diameter) generated a collimated electron beam by which very high resolution (> 16 lp/mm) X-ray imaging was achieved. (C) 2016 Elsevier Ltd. All rights reserved.