| 摘要 |
739,645. Cathode materials and processing. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Feb. 23, 1954 [Feb. 26, 1953], No. 5296/54. Drawings to Specification. Class 39 (1). In a dispenser cathode, the supply of emissive material contained in the internal cavity consists of a compact sintered mass of alkaline earth oxide, so prepared before closure of the cavity. This is formed by compressing the carbonate, such as barium-strontium carbonate, and then sintering. The sintering step may be carried out separately, in a platinum crucible in a vacuum oven for 5 minutes at 1500‹ C., or in place in the cathode body before finally closing the cavity, for 1 hour at 1000‹ C. and then 5 minutes at 1500‹ C. For the cylindrical type of cathode, the mass of carbonate may be preformed as a cylinder, or sectors thereof. |
