| 摘要 |
1,249,829. Cathode materials and processing. SIEMENS A.G. 25 Aug., 1969 [26 Aug., 1968], No. 42203/69. Addition to 1,177,590. Heading H1D. In the indirectly heated dispenser cathode arrangement of the parent Specification comprising a main dispenser cathode consisting of a porous carbon member impregnated with thorium oxide which is heated by the impact of the discharge from a secondary indirectly heated barium-based metal capillary cathode, this secondary cathode and the main dispenser cathode forming the cathode and anode respectively of a diode system having a separate discharge space, the thorium oxide impregnant is at least partially in crystalline form. The porous carbon anode member may initially be saturated with a 5% by weight solution of thorium-(IV) -acetylacetonate in acetylacetone until its pores are filled with the thorium compound, and after an initial drying at 100‹ C. the carbon member is heated in air at 500‹ C. for 5 minutes to convert the thorium compound to amorphous thorium oxide. Subsequent vacuum annealing at 1000‹ C. for 5 to 120 minutes converts the thorium oxide into the crystalline form. |
