Abstract:
An electron tube 10 is provided with: an MCP (electron multiplier) 14 which includes a multiplying portion 16 having a large number of microscopic holes for electron passage that can emit secondary electrons and a peripheral portion 18 that surrounds multiplying portion 16; and with a vacuum closed container 12 enclosing at least multiplying portion 16 of MCP 14. Thus, peripheral portion 18 of MCP 14 forms at least a portion of sidewalls 22 of vacuum closed container 12. Multiplying portion 16 is increased in size in this configuration in comparison with configurations having the same outer dimensions that accommodate the entirety of an MCP inside of vacuum closed container 12.
Abstract:
A cathode (5) for emitting photoelectrons or secondary electrons comprises a nickel electrode substrate (5c) with an aluminum layer (5b) deposited on it; an intermediate layer (5a) consisting of carbon nanotubes formed on the aluminum layer; and an alkaline metal layer (5d) formed on the intermediate layer (5a) and composed, for example, of particles of an alkali antimony compound that either emits photoelectrons in response to incident light or emits secondary electrons in response to incident electrons. The decrease in defect density of the particles reduces the probability of recombination of electron and hole remarkably, thus increasing quantum efficiency.
Abstract:
In a photomultiplier, focusing pieces of a focusing electrode are formed with sufficient height that the photocathode in the adjacent channels cannot be viewed from the first and second stage dynodes of each channel in order to prevent light reflected from the first and second stage dynodes from returning to the adjacent channels. This construction prevents the photocathode from emitting undesired electrons, thereby suppressing crosstalk. Further, by arranging condensing lenses on the outer surface of a light-receiving faceplate in correspondence with each channel, light is reliably condensed in each channel. Further, an oxide film formed. over the surface of the focusing pieces prevents the reflection of light off the focusing pieces.
Abstract:
A photomultiplier tube excellent in vibration resistance and having an anode with good pulse linearity characteristic. The photomultiplier tube has a mesh anode (A) composed of an anode frame (A11) and a mesh electrode (A12) supported and surrounded by the anode frame (A11). The central portion of one long side (A11B) of the anode frame (A11) serves as an electron converging part (F). The inner side of the anode frame (A11) swells toward the inner part of the anode (A), more from the middle of the long side (A11B) toward the corners of the anode frame (A11) along the long side (A11B), and therefore the thickness of the anode frame (A11) increases from the middle of the long side (A11) to the corners along the long side (A11B).