A novel vacuum-sealed field emission x-ray tube with graphene-gated carbon nanotube emitters

Multilayer graphene-gated carbon nanotube (CNT) emitters are introduced to novel vacuum-sealed x-ray tubes. We characterized field emission performances and electron-beam (Ebeam) converging of the graphene-gated emitter in a vacuum chamber. Thermal durability of the graphene-gate was well achieved to apply it to x-ray tubes processed with brazing at a high temperature. A transmissive anode target with a Be window, ceramic insulators, and the graphene-gated CNT emitters were successfully brazed to a fully vacuum-sealed x-ray tube, maintaining an unique graphene-gated field emission performance.