Properties and manufacture of top-layer scandate cathodes

Preparation and characterization of scandia and Re doped tungsten matrix impregnated cathode

“…This kind of tungsten powder covered with scandium oxide is an ideal powder for the production of scandate impregnated cathode. In 1980s, as reported by Hasker et al [2] the emission homogeneity and emission recovery after ion bombardment of the cathode made with tungsten particles covered with scandium oxide was better than the cathode made with a mixture of W and Sc 2 O 3 . In order to obtain this kind of powder, they prepared by mixing powders of W and ScH 2 , pressing the mixture in a mold followed by partial oxidation and sintering for 1 h in hydrogen atmosphere.…”

“…It had been widely demonstrated that scandate cathodes have highemission current density [1][2][3][4][5]. However, there was a common problem referring to non-uniformity in emission existing in all kinds of scandate cathodes.…”

Preparation and characterization of scandia-doped tungsten powders prepared by a spray-drying method

“…There are many remarkable advantages of scandate cathode compared with the ''M'' type cathode, i.e., the working temperature of scandate cathode can be reduced by 100-150°C, which is highly significant in vacuum electronic devices. It was found in previous work that the raw powder properties, for example morphology and particle size, greatly affected the emission property of the cathode [2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

Emission property of scandia and Re doped tungsten matrix dispenser cathode

“…An increase of electron emission current density at a given operating temperature is one of the main goals of thermionic cathode improvement for different applications in vacuum tubes. For thermionic cathodes, one of the most prospective candidates for the continuously improved vacuum devices in high emission current is scandate cathode [1][2][3][4][5][6][7][8]. However, the problems preventing high emission scandate cathodes from being widely utilized normally come down to a possible non-uniformity in emission, the susceptibility to ion bombardment damage and the poor reproducibility [9].…”