Abstract:
A III-V compound cathode is produced by exposing the cathode to cesium or cesium and oxygen, then exposing it to an increasing concentration of cesium while heating to about 150*C. The cathode is maintained at about 150*C, then exposed to a decreasing concentration of cesium while cooling. Also disclosed is an electron-emissive tube containing a cesium buffer source of a material incompletely reacted with cesium. The buffer source provides the increasing and decreasing concentrations of cesium for the above heating step.
Abstract:
An illustrative embodiment of the invention is directed to method and apparatus for manufacturing microchannel devices. Typically, the individual glass tubes in a hexagonal bundle are sealed on one end to individual hangers from which they are suspended vertically in a furnace. A vacuum is drawn within the furnace so that the inner surfaces of the tubes, exposed to atmospheric pressure, will not collapse during heating and drawing. At temperature, the bundle is drawn and elongates under the controlled forces applied through a modified Atwood''s machine to reduce the bundle cross section by a ratio of about 50 to 1. The elongated bundle is cut into lengths as it is drawn, and these individual lengths are stacked together within a tube of glass that has a higher melting point than the glass in the drawn lengths. The channels are once more sealed and the assemblies are subjected to a secondary fusion process prior to slicing into thin discs. The annular glass rings are removed from the discs and the microstructures are placed in a molten wax bath in order to fill the channels with wax before grinding and polishing. After grinding and polishing, the wax is removed.
Abstract:
The present invention relates to an alkali metal generating agent and others for formation of a photo-cathode or a secondary-electron emitting surface capable of stably generating an alkali metal. The alkali metal generating agent is used in formation of a photo-cathode for emitting a photoelectron corresponding to incident light, or in formation of a secondary-electron emitting surface for emitting secondary electrons corresponding to an incident electron. Particularly, the alkali metal generating agent contains at least an oxidizer comprising at least one vanadate with an alkali metal ion as a counter cation, and a reducer for reducing the ion. An alkali metal generating device comprises at least the alkali metal generating agent and a case housing it, and the case is provided with a discharge port for discharging the vapor of the alkali metal.