High current density Sc2O3-W matrix dispenser cathode

Sciece China. Information Sciences (Impact Factor: 0.7). 01/2011; 55(1). 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.

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