A Novel Back-Front Double-Gated Field Emission Electron Gun Using 3D CNT Emitters for X-Ray Source

We present a novel back-front double-gated triode electron gun (E-gun) structure that incorporates a 3D carbon nanotube (CNT) emitter. The E-gun includes three macro-size metal honeycomb meshes, with two serving as gates and one as a cathode, with directly grown CNTs on its surface. By biasing the two double gates simultaneously, a DC current of over 4.28 mA was achieved, almost double compared to the collective current when each gate was biased individually. This increase in current is attributed to the unique design of the E-gun structure, which allows maximum participation of CNTs and is also confirmed by the simulation.