Fast warm=up cathode heater assembly - for electron discharge device

摘要

The heat-cathode assembly comprises (a) a pure, hexagonal crystal alpha-Al2O3 substrate, (b) a metallised layer centrally located on one surface and (c) a second metallised layer on the opposite surface having a (partially) serpentine configuration which is aligned with the first layer. Pref. a single metallised connector extends from the first metallised layer to a first edge of the substrate and an electron emissive material is coated on the first metallised layer. The assembly is simply and economically constructed and has a warm up time of 2.5 s.