Abstract:
The faceplate of a light detector tube is provided with an internal photocathode having wedge-shaped projections and external lenses to concentrate the light from a source onto the projecting photosensitive surface areas. An accelerating grid having a corresponding configuration is spaced closely to the photocathode to increase the emission of electrons from the photosensitive surface. A potential source establishes an electric field between the photocathode and an anode, with the anode collecting the electrons.
Abstract:
An illustrative embodiment of the invention shown a method and apparatus for joining a crystalline magnesium fluoride faceplate to the envelope of a photomultiplier tube. The bialkali photocathode deposited on the faceplate is protected from the chemically incompatible silver chloride sealing compound by a preglazed glass frit that acts as a barrier between the photocathode and the seal.
Abstract:
A multiple total reflection optical device is disclosed with angled ends on optical wave guides in a bundle of optical wave guides. In one embodiment a photocathode imaging system is disclosed wherein the terminal fused plate of a fiber optic bundle is selectively etched to produce a taper at the end of each fiber which is then coated with a photocathode material. Light conducted through the fibers undergoes multiple total reflections down the terminal taper and is dissipated with high efficiency in the photocathode material. The tapered ends can be cones, corner cubes or other shapes.
Abstract:
When a scale grid undergoes movement relative to index grids superposed on and adhering to respective photoelectric devices, the resulting variation in a bright-dark pattern formed by the grids is detected by the photoelectric devices and converted into electrical signals, which are processed and digitally displayed or utilized for control of machines and equipment.