Characteristics of scandate-impregnated cathodes with sub-micron scandia-doped matrices

Ab initio investigation of the surface properties of dispenser B-type and scandate thermionic emission cathodes

“…1 Their copious electron emission capabilities are believed to stem from a low work function ͑⌽͒, a consequence of the barium ͑Ba͒, scandium ͑Sc͒, and oxygen ͑O͒ chemical complex forming on the tungsten ͑W͒ surface. [2][3][4][5][6][7][8][9][10] Figure 1 shows the measured practical ⌽ distribution 11 of a scandate cathode with ⌽ = 1.32 eV. The scandate cathode can be thought of as a modification of the traditional B-type dispenser cathode, which has only Ba and O on the W surface and where the observed reduction in ⌽ relative to pure W is attributed to the formation of Ba-O surface dipole monolayers.…”

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

“…It shows that s (0.06) of scandia and Re co-doped tungsten matrix impregnated cathode is much less than that (0.14) of the cathode prepared in our previous work without adding Re [10], indicating that scandia and Re co-doped tungsten matrix impregnated cathode provided uniform emission, see Fig. 4a.…”

“…4a. Whereas, the cathode prepared in our previous work [10] without adding Re showed relatively poor emission uniformity (Fig. 4b).…”

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].…”