Photomultiplier

An electron multiplier comprising a dynode unit including a plurality of stacked stages of dynode plates, said dynode plates being spaced apart from each other at predetermined intervals by insulating members in an incidence direction of electrons, for respectively supporting at least one dynode for cascade multiplying incident electrons, each of said dynode plates having

• a first depression in which a first insulating member is provided, said first depression being formed on a first main surface of said dynode plate and said first insulating member is in partial contact with said first depression;
• and
• a second depression in which a second insulating member is provided, said second depression being formed on a second surface of said dynode plate opposing said first main surface, said second insulating member being in partial contact with said second depression, said second depression communicating with said first depression through a through hole,
• wherein said first insulating member and said second insulating member are in direct contact with each other in said through hole;
• and
• wherein said insulating members are in contact at contact points on a surface of said members, wherein said contact points define a substantially straight line.

An electron multiplier comprising:

• a dynode unit comprising:
• a plurality of stacked stages of dynode plates, said dynode plates being spaced apart from each other by predetermined intervals using insulating members as spacers in an incidence direction of the electrons, for respectively supporting at least one dynode for cascade-multiplying incident electrons,
• each of said dynode plates having
• a first depression supporting a first insulating member and being provided on a first main surface of said dynode plate and said first insulating member is in partial contact with said first depression;
• and
• a second depression supporting a second insulating member and being provided on a second main surface opposing said first main surface and said second insulating member is in partial contact with said second depression, said second depression communicating with said first depression through a through hole,
• wherein an interval between a contact portion between said first depression and said first insulating member and a contact portion between said second depression and said second insulating member is smaller than that between said first and second main surfaces of each of said dynode plates;
• and
• wherein said insulating members are in contact at contact points on a surface of said members, wherein said contact points define a substantially straight line.

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, said dynode unit comprising a plurality of stacked stages of dynode plates, said dynode plates spaced apart from each other at predetermined intervals via insulating members that separate said dynode plates in an incident direction of photoelectrons emitted from said photocathode, for respectively supporting at least one dynode for cascade-multiplying said photoelectrons,
• wherein each of said dynode plates has
• a first depression supporting a first insulating member and being provided on a first main surface of said dynode plate, said first insulating member being in partial contact with said first depression;
• and
• a second depression supporting a second insulating member and being provided on a second main surface opposing said first main surface, said second insulating member being in partial contact with said second depression, said second depression communicating with said first depression through a through hole,
• wherein said first insulating member and said second insulating member are in direct contact with each other in said through hole;
• and
• wherein said insulating members are in contact at contact points on a surface of said members, wherein said contact points define a substantially straight line.

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 comprising a plurality of stacked stages of dynode plates, said dynode plates for respectively supporting at least one dynode for receiving and cascade-multiplying photoelectrons emitted from said photocathode in an incidence direction of said photoelectrons,
• wherein each of, said dynode plates has
• a first depression supporting a first insulating member and being provided on a first main surface of said dynode plate, said first insulating member being in partial contact with said first depression;
• and
• a second depression supporting a second insulating member and being provided on a second main surface opposing said first main surface, said second insulating member being in partial contact with said second depression, said second depression communicating with said first depression through a through hole,
• wherein an interval between a contact portion between said first depression and said first insulating member and a contact portion between said second depression and said second insulating member is smaller than an interval between said first and second main surfaces of each of said dynode plates;
• and
• wherein said insulating members are in contact at contact points on a surface of said members, wherein said contact points define a substantially straight line.