Effect of Impregnation on the Performance of Sc2O3-doped Tungsten Matrix Cathodes

keywords:scandate cathodes  impregnation  Sc2O3-doped tungsten matrix  life reliability

Abstract:High emission and long lifetime scandate cathode is one of the key research directions of high current density cathodes.In order to improve the working stability and increase the proportion of scandium element on the surface of cathodes, a combination of scandate cathodes was obtained based on the high uniform Sc2O3-doped tungsten matrix and high emission scandate. In this paper, the impregnation effect on the emission performance and lifetime of Sc2O3-doped tungsten matrix cathodes are investigated. The results show that the active substance is fully filled in the matrix when the impregnation amount is larger than 6. 4 wt% and the obtained scandate cathode can work stably in the low vacuum environment with high current density of 20 A/ cm2 for more than 400 Hrs.