| 摘要 |
Cathode including a solid body (4) which comprises metallic constituents (particularly W, Ni, Mg, Re, Mo, Pt) and oxidic constituents (such as particularly BaO, CaO, Al2O3, Sc2O3, SrO, ThO2, La2O3). Also at low operating temperatures, high emission current densities and a long lifetime are achieved in that the structure of the constituents and the volume ratio vm of the metallic constituents relative to the overall volume of the solid body are chosen to be such that the resistivity rho has a value in the range of rho 0x10-4> rho > rho mx102, in which rho 0 and rho m are the resistivities, defined at 20 DEG C., of the pure oxidic constituents and the pure metallic constituents, respectively.
|
