Electron multiplier for forming a photomultiplier and cascade multiplying an incident electron flow using multilayerd dynodes

A photomultiplier comprising:

• a photocathode;
• an anode plate for supporting at least one anode;
• a dynode unit provided between said photocathode and said anode plate and formed by stacking a plurality of stages of dynode plates in an incident direction of photoelectrons emitted from said photocathode such that a last-stage dynode plate of said dynode unit opposes in parallel said anode plate, spaced apart from each other through insulating members at predetermined intervals, each of said dynode plates adapted to support at least one dynode for cascade-multiplying said photoelectrons;
• and
• a plurality of connecting pins, each adapted to be engaged with one of said dynode plates for applying a desired potential thereto, wherein
• each of said dynode plates having an engaging member adapted to be engaged with a corresponding one of said connecting pins at a predetermined portion of a side surface thereof in parallel to the incident direction of said photoelectrons, and said predetermined portions of said dynode plate adjacent to each other do not cause said engaging members to overlap each other in a stacking direction of said dynode plates.

A photomultiplier comprising:

• a housing for fabricating a vacuum container, having a light receiving plate;
• a photocathode deposited on a surface of said light receiving plate, said photocathode provided in said housing;
• a dynode unit constituted by stacking a plurality of stages of dynode plates in an incident direction of photoelectrons emitted from said photocathode, each of said dynode plates adapted to support at least one dynode for receiving and cascade-multiplying said photoelectrons;
• a plurality of connecting pins, each adapted to be connected to one of said dynode plates for applying a desired potential thereto;
• a base member integrally formed with said housing to form said vacuum container and having said dynode unit mounted thereon and through holes for guiding said plurality of connecting pins;
• and
• an anode plate for supporting at least one anode provided between said dynode unit and said base member, wherein
• each of said dynode plates which constitutes said dynode unit has an engaging member adapted to be engaged with a corresponding one of said connecting pins at a predetermined portion of a side surface thereof in parallel to the incident direction of said photoelectrons, and said predetermined portions of said dynode plates adjacent to each other do not cause said engaging members to overlap each other in a stacking direction of said dynode plates.