Title :
The M-type cathode - No longer magic?
Author_Institution :
Varian Associates, Inc., Palo Alto, California
Abstract :
Recent progress in the understanding and quantification of the surface effects occurring in M-type and mixed metal matrix cathodes is described. A new mechanism for the mode of emission enhancement in these cathodes is proposed based on chemical rather than physical effects. A correlation has been established between the formation of osmium/tungsten alloy and reduced effective work function. Using this result an improved dispenser cathode has been constructed with a work function 0.2 eV lower than conventional B-type emitters.
Keywords :
Barium; Cathodes; Chemicals; Current measurement; History; Life testing; Manufacturing; Performance evaluation; Spatial resolution; Tungsten;
Conference_Titel :
Electron Devices Meeting, 1980 International
Conference_Location :
Washington, DC, USA
DOI :
10.1109/IEDM.1980.189869
