| 摘要 |
1,182,150. Cathode processing. S.A.E.S. GETTERS S.p.A. 13 Dec., 1967 [13 Dec., 1966; 12 Oct., 1967], No. 56641/67. Heading HID. An alkali metal vapour dispenser comprises a container 1 provided with a slot 2 through its wall and containing a mixture of particles 3 including an alkali metal chromate, a reducing agent, and a proportion of very fine particles of a metal which can be at least partially sintered at temperatures below 600‹ C. and has a vapour pressure substantially lower than that of the alkali metal released when decomposition of the alkali metal chromate takes place. The sinterable metal may be Fe, Ni, Co or Ti. A getter material may be added to the mixture to prevent the evolution of O 2 and H 2 O during the reduction. The getter may be Zr or Zr alloy which acts also as a reducing agent. Alternatively the reducing agent may be Si. The container 1 is of stainless steel or Ni-Cr alloy having a trapezoidal cross-section and sealed by pressing the ends 5 around terminal wires 4. The mixture can be degassed and sintered at temperatures of 550-600‹ C. without evolution of alkali metal vapour. The sintering prevents the escape of particles from the container. The dispenser may be used in electron discharge tubes to liberate Cs when forming photo-sensitive surfaces. |
