High current density Sc2O3-W matrix dispenser cathode

ArticleinSciece China. Information Sciences 55(1) · January 2011with18 Reads
Impact Factor: 0.85 · DOI: 10.1007/s11432-011-4518-y · Source: DBLP

    Abstract

    Sc2O3-W matrix dispenser cathodes have been prepared by powder metallurgy method and tested in Pierce electron guns. The emission current density can reach 72 A/cm2 at 900°C and over 100 A/cm2 can be achieved at a temperature higher than 950°C. The emission improves and then keeps stable with time throughout the life testing period of 330 h at a continuous loading of 88 A/cm2 pulsed current density with a pulse width of 10 μs and duty cycle of 0.2%. The cathode surface is covered by a semiconductor multilayer composed of Ba, Sc and O. The emission behavior of the cathode can be explained by a semiconductor model.