OXIDE CATHODE AND PRIMARY GRID EMISSION STUDIES.
Monthly rept. no. 8 for Dec 47,
WESTINGHOUSE ELECTRIC CORP BLOOMFIELD NJ LAMP DIV
Pagination or Media Count:
From photographic study of synchroscope traces it appears that arcing in 715 type tubes may take place between any elements of the tube. The most frequent type of breakdown of those observed seems to be that in which the control grid acts as cathode of the arc, while those in which the screen grid acts as the arc cathode are relatively infrequent. Although most cases of breakdown occur during the pulse or a few microseconds later, this is not necessarily the case. Chemical analysis, in conjunction with spectroscopic analysis, indicate that the source of the interfering line in the x-ray diffraction pattern of molybdenum is not due to barium contamination as previously suspected. The material evaporated from an oxide cathode begins to evaporate from Svea metal at about 1010 K. The maximum thermionic emission obtained from Svea metal was approximately 1.0 masq. cm. The emission from fully contaminated tungsten is always at least five times that from Svea metal at the same temperature. Author