Abstract:
A method of manufacturing an electric discharge tube having an electron-emitting electrode comprising a support with a cesiumcontaining layer thereon which is activated by reaction of a gaseous compound of an inactive or inert gas and fluorine until a cesium fluoride layer having a composition (CsF, Cs) is formed. The gaseous compound, at the temperatures prevailing in the tube does not react with the surfaces of other parts.
Abstract:
A microchannel plate has a platelike photosensitive glass substrate and a plurality of microchannels formed separately from each other and extending across the thickness of the substrate. A secondary electron-emission surface is formed on an inner surface of each of the microchannels. Accelerating electrodes formed on two opposite sides of the photosensitive glass substrate, so as to be partially in electrical contact with the secondary-emission surface. The microchannels are formed by applying ultraviolet rays to the substrate through a mask and removing irradiated portions of the substrate by etching.
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:
A dynode structure which emits electrons in response to incident electrons or incident light consists of a thin layer of galliumarsenide which is formed integrally with a surrounding frame of gallium-arsenide. The structure is robust and straight forward to produce.
Abstract:
A method comprising coating an uncontaminated emitter surface of an emitter body with a non-contaminating protective layer and then mounting the body so that the coated surface is in the interior of an envelope. The envelope and body are then heated to a first temperature to drive contaminant gases from surfaces of the envelope interior while these gases are simultaneously pumped out. The first temperature is low enough that the protective layer remains. Then the body is heated to a second temperature, higher than the first, and the protective layer evaporated off the surface while the envelope is maintained at a temperature below the first temperature. Thereafter the emitter surface is activated by the application thereto of a material which lowers the work function.
Abstract:
A reflective type photocathode of a photomultiplier includes a porous antimony layer in overlay relation to a layer of solid antimony along a supporting substrate.
Abstract:
In a photomultiplier tube, antimony layers of a photocathode and a plurality of dynodes are simultaneously sensitized by exposure to the vapors of sodium and potassium at an initial temperature of less than about 120.degree. C. The temperature of exposure is gradually increased at a rate of less than about 10.degree. C. per minute until a final temperature of about 200.degree. C. is reached. Then, the photocathode and dynodes are baked at the final temperature until substantially maximum photosensitivity is achieved. The photocathode and dynodes are thereafter exposed to cesium and may be superficially oxidized until substantially maximum photosensitivity is achieved.
Abstract:
Monoatomic layers to reduce the work function of photocathodes, secondary emission electrodes and field emission electrodes are obtained by surface segregation as a result of a thermal treatment after preceding indiffusion of the activator. Examples are in particular p-semiconductors such as silicon and III-V compounds with alkali metals.