Tungsten-rhenium mixed metal matrix cathodes

In this paper, studies are carried out on W-Re mixed matrix cathodes developed in house, will be discussed. It has been observed that a proper choice of rhenium particle size is essential for obtaining good emission density. The cathodes have been prepared by impregnating W-Re (50%-50% by weight) mixed metal matrices with 5:3:2 barium calcium aluminates. A current density of 20 A/cm
²
has been achieved at 1360K. Life testing of these cathodes has been carried out in closely spaced diode configuration. Variation of work function and emission current density after 35000 Hrs of life will be presented.