Photomultiplier for cascade-multiplying photoelectrons

A photomultiplier comprising:

• a housing for fabricating a vacuum container;
• a photocathode provided in said housing;
• an anode provided in said housing;
• an electron multiplier for cascade-multiplying photoelectrons emitted from said photocathode, said electron multiplier provided between said photocathode and said anodes in said housing;
• and
• a focusing electrode plate for supporting at least one focusing electrode for correcting orbits of the photoelectrons emitted from said photocathode, provided between said photocathode and said electron multiplier, and fixed on a photoelectron incident side of said electron multiplier through insulating members, said focusing electrode plate having
• holding springs integrally formed with said focusing electrode plate and pressed against an inner wall of said housing to hold an arrangement position of said electron multiplier.

A photomultiplier comprising:

• a housing for fabricating a vacuum container;
• a photocathode provided in said housing;
• an anode provided in said housing;
• an electron multiplier for cascade-multiplying photoelectrons emitted from said photocathode, said electron multiplier provided between said photocathode and said anodes in said housing;
• and
• a focusing electrode plate for supporting at least one focusing electrode for correcting orbits of the photoelectrons emitted from said photocathode, provided between said photocathode and said electron multiplier, and fixed on a photoelectron incident side of said electron multiplier through insulating members, said focusing electrode plate having:
• holding springs integrally formed with said focusing electrode plate and pressed against an inner wall of said housing to hold an arrangement position of said electron multiplier;
• and
• at least one contact terminal integrally formed with said focusing electrode plate and brought into direct contact with said photocathode to equalize potentials of said photocathode and said focusing electrode plate.

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 constituted by stacking a plurality of stages of dynode plates such that a last-stage dynode plate of said dynode unit opposes said anode plate in parallel, said dynode plates spaced apart from each other at predetermined intervals through insulating members in an incident direction of photoelectrons emitted from said photocathode, each dynode plate for supporting at least one dynode for cascade-multiplying said photoelectrons;
• and
• a focusing electrode plate for supporting at least one focusing electrode and for focusing and guiding the photoelectrons emitted from said photocathode to a first-stage dynode plate, said focusing electrode plate opposing said first-stage dynode plate of said dynode unit, fixed parallel to said dynode unit through insulating members, and having
• a concave portion for arranging an insulating member which is partially in contact with said concave portion on a first main surface opposing at least said first-stage dynode plate,
• wherein a gap is formed between a main surface of said concave portion and a surface of said insulating member to prevent discharge between said focusing electrode plate and said first-stage dynode plate which opposes said focusing electrode plate.

A photomultiplier comprising:

• a housing for fabricating a vacuum container, having a light receiving plate and a conductive metal film formed in a predetermined region of an inner wall;
• a photocathode deposited on a surface of said light receiving plate 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 said dynode plate for supporting at least one dynode for receiving and cascade-multiplying said photoelectrons;
• a base member, integrally formed with said housing and having said dynode unit mounted thereon, for guiding a plurality of connecting pins for applying a predetermined voltage to said dynode plates for constituting said dynode unit;
• an anode plate for supporting at least one anode provided between said dynode unit and said base member;
• a focusing electrode plate for supporting at least one focusing electrode for correcting orbits of the photoelectrons emitted from said photocathode, provided between said photocathode and said dynode unit, and fixed on an electron incident side of said dynode unit through insulating members, said focusing electrode plate having
• holding springs pressed against said inner wall of said housing, where said conductive metal film is formed, to hold an arrangement position of said dynode unit, and said holding springs and said focusing electrode plate being integrally formed;
• and
• a conductive metal member for electrically connecting said conductive metal film formed on said inner wall of said housing, which is in contact said holding springs, to said photocathode to equalize potentials of said focusing electrode plate and said photocathode.

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 constituted by stacking a plurality of stages of dynode plates in an incident direction of photoelectrons emitted from said photocathode, each said dynode plate for supporting at least one dynode for receiving and cascade-multiplying said photoelectrons;
• a base member, integrally formed with said housing and having said dynode unit mounted thereon, for guiding a plurality of connecting pins for applying a predetermined voltage to said dynode plates for constituting said dynode unit;
• an anode plate for supporting at least one anode provided between said dynode unit and said base member;
• and
• a focusing electrode plate for supporting at least one focusing electrode for correcting orbits of the photoelectrons emitted from said photocathode, provided between said photocathode and said dynode unit, and fixed on a photoelectron incident side of said dynode unit through insulating members and having
• holding springs pressed against an inner wall of said housing, where a conductive metal film is formed, to hold an arrangement position of said dynode unit, said holding springs and said focusing electrode plate being integrally formed, and
• at least one contact terminal brought into direct contact with said photocathode to equalize potentials of said photocathode and said focusing electrode plate, said contact terminal and said focusing electrode plate being integrally formed.