Photomultiplier including an electron multiplier for cascade-multiplying an incident electron flow using a multilayered dynode

A photomultiplier comprising:

• a photocathode;
• an anode plate for supporting at least one anode;
• and
• a dynode unit provided between said photocathode and said anode plate and having a plurality of stages including a plurality of dynode plates stacked in an incident direction of electrons, said dynode plates spaced apart from each other by insulating members at predetermined intervals such that a last-stage dynode plate of said dynode unit opposes in parallel to a front surface of said anode plate, each said dynode plate supporting at least one dynode for cascade-multiplying photoelectrons emitted from said photocathode and being integrally formed by welding at least two plates overlapping each other in a stacking direction of said dynode plates,
• wherein a welding position of said at least two plates that overlap each other to form one of said dynode plates of said dynode unit does not overlap in the stacking direction of said dynode plates a welding position of an adjacent dynode plate formed from another of said at least two plates.

A photomultiplier comprising:

• a housing for fabricating a vacuum container, said housing having a light receiving plate;
• a photocathode deposited on a surface of said light receiving plate in said housing;
• a dynode unit having a plurality of stages including a plurality of dynode plates stacked in an incident direction of photoelectrons emitted from said photocathode, said dynode plates spaced apart from each other by insulating members at predetermined intervals, each said dynode plate supporting at least one dynode for cascade-multiplying the photoelectrons emitted from said photocathode and being integrally formed by welding at least two plates overlapping each other in a stacking direction of said dynode plates;
• a base member having said dynode unit mounted thereon and being integrally formed with said housing to constitute said vacuum container having said dynode unit arranged therein;
• and
• an anode plate, provided between said dynode unit and said base member, for supporting at least one anode, said anode plate opposing in parallel to a last-stage dynode plate of said dynode unit through insulating members,
• wherein a welding position of said at least two plates that overlap each other to form one of said dynode plates of said dynode unit does not overlap in the stacking direction of said dynode plates a welding position of an adjacent dynode plate formed from another of said at least two plates.