Title :
DC Emission Characteristic of Nanosized-Scandia-Doped Impregnated Dispenser Cathodes
Author :
Wenlong Liang ; Yiman Wang ; Jinshu Wang ; Wei Liu ; Fan Yang
Author_Institution :
Sch. of Mater. Sci. & Eng., Beijing Univ. of Technol., Beijing, China
Abstract :
To meet the requirements for advanced vacuum electron devices and modern electron beam instruments, dc emission properties of nanosized-scandia-doped impregnated (SDI) cathodes have been investigated in a closely spaced diode configuration system with water-cooled copper anode. The SDI cathodes were made from nanosized-scandia-doped tungsten powder, which was produced by a spray-drying process. A space-charge-limited dc current density of over 60 A/cm2 has been measured at 950 °Cb. An on-going life test with a dc load of 30 A/cm2 at 950 °Cb has completed more than 2000 h of operation to date. The electron cooling for dc beam emission is discussed.
Keywords :
cathodes; current density; drying; electron field emission; life testing; powder technology; scandium; space charge; spraying; tungsten; DC beam emission characteristic; SDI cathodes; W:Sc; advanced vacuum electron devices; closely spaced diode configuration system; electron beam instruments; electron cooling; nanosized-scandia-doped impregnated dispenser cathodes; nanosized-scandia-doped tungsten powder; on-going life test; space-charge-limited dc current density; spray-drying process; temperature 950 degC; water-cooled copper anode; Cathodes; Current density; Density measurement; Powders; Temperature measurement; Tungsten; Scandate cathode; thermionic emission; vacuum electron devices (VEDs); vacuum electron devices (VEDs).;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2014.2319298
