Scandia doped impregnated cathode prepared by spray drying method

Abstract

The scandia doped tungsten powders have been obtained by a new method of spray drying combined with two-step reduction in hydrogen atmosphere. The impregnated cathode prepared with the obtained powders has an excellent emission capability of 121 A/cm2 at 950 °C b in pulsed condition. The DC life test result indicates that the emission current density of 40 A/cm2 has lasted up to 4000 hours.