Study of emission properties and evaporation rate of impregnated tungstate cathode

Tungstate cathodes have been prepared by impregnating a mixture of the barium-strontium tungstate and zirconium hydride at 1840 °C
_b
. Emission characteristics and evaporation properties were tested. The result shows that the dc emission current density reaches 4.30A/cm
²
at 1000 °C
_b
, 7.54A/cm
²
at 1050 °C
_b
, 9.43A/cm
²
at 1100 °C
_b
. The evaporation rate of the cathode is lower than an uncoated aluminate cathode.