Title :
Oxide cathodes produced by plasma deposition
Author :
Scheitrum, G. ; Caryotakis, G. ; Pi, T. ; Umstattd, R. ; Brown, I. ; Montiero, O.
Author_Institution :
Linear Accel. Center, Stanford Univ., CA, USA
Abstract :
Summary form only given. The best oxide cathodes have been capable of long life and high-current-density. The problem has been the ability to consistently reach maximum performance. The complex chemistry of the deposition and activation process have made consistent performance unrealizable. SLAC, UCD, and LBL are developing a plasma deposition process that eliminates the problems with binders, carbonate reduction, peeling, and porosity. The emission layer is deposited using plasma deposition of metallic barium in vacuum with an oxygen background gas. An applied bias voltage drives the oxide plasma into the nickel surface. Since the oxide is deposited directly, it does not have problems with poisoning from hydrocarbon binder. The density of the oxide layer is increased from the 40% to 50% for standard oxide cathodes to nearly 100% for plasma deposition. It is expected that the repeatable process, increased density, and elimination of poisoning agents will provide a long-life, high-current-density cathode for a variety of applications.
Keywords :
beryllium compounds; oxide coated cathodes; plasma deposited coatings; plasma deposition; BeO; Ni; Ni surface; O/sub 2/ background gas; activation process; deposition; emission layer; high-current-density cathode; metallic Ba; oxide cathodes; oxide layer; oxide plasma; plasma deposition process; Cathodes; Electrons; Laboratories; Plasma accelerators; Plasma applications; Plasma chemistry; Plasma density; Plasma devices; Plasma simulation; Plasma sources;
Conference_Titel :
Plasma Science, 1997. IEEE Conference Record - Abstracts., 1997 IEEE International Conference on
Conference_Location :
San Diego, CA, USA
Print_ISBN :
0-7803-3990-8
DOI :
10.1109/PLASMA.1997.604802