Patent ID: 7102284

Claim:
A photomultiplier comprising: a light-receiving faceplate; a wall section forming a vacuum space with the light-receiving faceplate; a photocathode formed inside the vacuum space on an inner surface of the light-receiving faceplate and having a plurality of channels, wherein each channel emits electrons in response to light incident thereon; an electron multiplying section disposed inside the vacuum space and having a plurality of secondary electron multiplying pieces having a one-on-one correspondence with the plurality of channels for multiplying electrons emitted from each channel in the photocathode for the corresponding channel; an anode disposed within the vacuum space for generating an output signal for each channel based on the electrons multiplied for each channel by the electron multiplying section; and a focusing electrode disposed in the vacuum space and having a plurality of focusing pieces, wherein two adjacent focusing pieces define an opening corresponding to one channel, such that electrons emitted from corresponding channel of the photocathode are focused by the opening and guided to the corresponding channel of the electron multiplying section, and the adjacent focusing pieces are configured to prevent extraneous light reflected off the surface of secondary electron multiplying pieces in the corresponding channel of the electron multiplying section from reaching channels adjacent to the corresponding channel of the photocathode.