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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 900C and over 100 A/cm2 can be achieved at a temperature higher than 950C.The emission improves and then keeps stable with time throughout the life testing period of 330 h at a continuous loading of 88 A/cm2pulsed current density with a pulse width of 10μs 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.
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 900C and over 100 A / cm2 can be achieved at a temperature higher than 950C. improves and then keeps stable with time throughout the life testing period of 330 h at a continuous loading of 88 A / cm2pulsed current density with a pulse width of 10μs and duty cycle of 0.2%. 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.