Improvement of mechanical strength for Nanosized-Scandia Doped Dispenser cathodes

摘要

In order to improve the mechanical strength and machining properties of Scandia Doped Dispenser (SDD) cathodes when they are applied into Vacuum Electron Devices (VEDs), an effort has been expended to increase the W grain sizes while maintaining the uniform doping of nanosized Scandia particle. By an improved liquid-solid (L-S) doping process, powders composed of W grains of about 1-2 micron in diameters with uniformly distributed nanosized scandium oxide particles have been fabricated. Cathodes constructed by above powders exhibited better properties in machining operations like lathing, and similar emission characteristics to that of SDD cathodes made from the powders with liquid-liquid doping methods.