| 摘要 |
795,566. Cathode materials. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Feb. 6, 1956 [Feb. 9, 1955], No. 3626/56. Drawing to Specification. Class 39(1). In a dispenser cathode in which the emissive material is dispersed throughout a body of porous refractory metal, said material consists of a fused mixture of (a) barium oxide, (b) aluminium oxide and/or boric oxide, and (c) one or more of the oxides of calcium, strontium, and magnesium ; the mole ratio of (a) to (b) is in excess of 1 : 1. The cathode may be made either by compressing and heating a powdered mixture of the refractory metal and the prefused compounds, or by impregnation. Preferred proportions of materials, and temperatures, are given for each of these methods. Some experimental data showing relative emission for various proportions of constituent materials is given. Specifications 734,209 and 734,311 are referred to. |
