Scandia doped impregnated cathode prepared with hollow tungsten spheres

Abstract

The scandia doped tungsten powders have been obtained by a new method of spray drying combined with two-step reduction in hydrogen atmosphere. Based on the powders, the cathode impregnated with 612 aluminates (SDI-612) has excellent emission capability of 72.2A/cm² at 900^oC_b, moreover, the SDI-612 cathode has a lower evaporation rate of 8.45*10^-9g.cm^-2s^-1 at 1150^oC_b.