Patent ID: 7449834
Filing Date: 2008-11-11
Classification: H01J

Abstract:
1. A photomultiplier comprising: a sealed container including a hollow body section extending along a predetermined tube axis, and a faceplate provided so as to intersect the tube axis, said faceplate transmitting light with a predetermined wavelength; a photocathode provided inside the sealed container so as to emit photoelectrons into said sealed container in response to incidence of the light with the predetermined wavelength; and an electron multiplier section provided inside the sealed container so as to cascade-multiply photoelectrons emitted from said photocathode, said electron multiplier section including: at least two dynode sets arranged so as to sandwich the tube axis, each of said dynode sets being constituted by a plurality of dynodes that respectively have a secondary electron emitting surface; and a pair of insulating supporting members that clampingly and integrally hold said two dynode sets excluding at least first dynodes at which photoelectrons from said photocathode arrive and which are arranged in a manner such that respective back surfaces of said first dynodes, which oppose the respective secondary electron emitting surfaces thereof, face each other while sandwiching the tube axis, wherein said pair of insulating supporting members have pedestal portions arranged so as to face said photocathode, said first dynode belonging to each of said two dynode sets being mounted on both pedestal portions of said pair of insulating supporting members while the back surface of said first dynode is in direct contact with both pedestal portions of said pair of insulating supporting members.