Fast turn-on osmium coated cathode
Abstract
This abstract discloses a fast turn-on refractory coated cathode comprising a porous tungsten metal matrix impregnated with barium calcium aluminate and coated with osmium. The osmium coating has a planned series of interruptions with each interruption being on the order of several microns in width to thereby expose the tungsten. These interruptions permit the barium and oxygen from the impregnant to rise to the cathode surface during activation or reactivation to form a desired near monolayer of barium and oxygen to enhance electron emission. Thus, this cathode design provides a fast turn-on characteristic even after shelf storage.
- Publication:
-
Patent Application Department of the Navy
- Pub Date:
- March 1984
- Bibcode:
- 1984padn.reptR....M
- Keywords:
-
- Cathodes;
- Electrode Materials;
- Metal Coatings;
- Osmium;
- Activation;
- Aluminates;
- Barium Compounds;
- Calcium Compounds;
- Electron Emission;
- Impregnating;
- Interruption;
- Matrix Materials;
- Oxygen;
- Patent Applications;
- Porous Materials;
- Reaction Time;
- Refractory Coatings;
- Starting;
- Surface Layers;
- Tungsten;
- Electronics and Electrical Engineering