Patent ID: 7115854

Claim:
A photomultiplier, comprising: a sealed container having an entrance face plate partitioned into a plurality of light incidence regions, and a stem opposing said entrance face plate; a photocathode emitting photoelectrons into said sealed container in response to light having passed through said entrance face plate; a plurality of anodes respectively prepared for electron multiplier channels which are assigned to said light incidence regions partitioned on said entrance face plate, and being respectively positioned inside said sealed container so as to oppose said associated light incidence regions; and a dynode unit housed in said sealed container, disposed between said anodes and said photocathode, and constituted by N (an integer of no less than 3) dynode plates, each of said dynode plates being provided with an electron multiplier hole for the associated channel, concerning all channels, and being arranged at a position corresponding to the associated one of said plurality of light incidence regions, wherein a n-th (an integer of no less than 2) dynode plate in said dynode unit is constituted by a plurality of control plates each having an electron multiplier hole for the associated channel and being electrically and physically separated from the others, and wherein said control plates are supported in a state of being sandwiched, via insulators, by a (n−1)-th dynode plate and a (n+1)-th dynode plate.