FIELD EMISSION COLD CATHODE

摘要

A field emission cold cathode (11) for use in vacuum tubes. A carbon velvet material (25) is comprised of high aspect ratio carbon fibers embedded perpendicular to a base material. The tips and/or the shafts of the carbon velvet material (25) are coated with a low work function cesiated salt. The base material of the carbon velvet material (25) is bonded to a cathode surface (27). The cold cathode (11) emits electrons when an electric field i s applied, even at operating temperatures less than 900~C.