| US 7,498,741 B2 | ||
| Photomultiplier including a seated container, photocathode, and a dynode unit | ||
| Toshikazu Fujita, Hamamatsu (Japan) | ||
| Assigned to Hamamatsu Photonics K.K., Hamamatsu-shi, Shizuoka (Japan) | ||
| Filed on Oct. 28, 2005, as Appl. No. 11/260,259. | ||
| Claims priority of provisional application 60/666627, filed on Mar. 31, 2005. | ||
| Prior Publication US 2006/0220552 A1, Oct. 05, 2006 | ||
| Int. Cl. H01J 40/16 (2006.01) | ||
| U.S. Cl. 313—537 [313/532; 313/308] | 5 Claims |
| 1. A photomultiplier comprising:
a sealed container of which the inside is kept in a vacuum state;
a photocathode, accommodated in said sealed container, for emitting photoelectrons to the inside of said sealed container
in response to light having a predetermined wavelength;
a dynode unit accommodated in said sealed container and including a plurality of stages of dynodes for emitting secondary
electrons in response to the photoelectrons reached from said photocathode to cascade-multiply sequentially the secondary
electrons;
an anode, accommodated in said sealed container, for taking the secondary electrons cascade-multiplied by said dynode unit
as a signal;
a pair of insulating support members for holding unitedly said dynode unit and said anode in a state grasping said dynode
unit and said anode;
a focusing electrode arranged between said photocathode and said dynode unit and having a through hole through which the photoelectrons
from said photocathode pass, said focusing electrode for correcting an orbit of each photoelectron from said photocathode;
and
an accelerating electrode, arranged between said focusing electrode and said dynode unit, and having a through hole through
which the photoelectrons reached from said photocathode via said focusing electrode pass, said accelerating electrode for
accelerating the photoelectrons reached from said photocathode via said focusing electrode,
wherein said accelerating electrode has: a lower electrode that is held by said pair of insulating support members in a state
for said pair of insulating support members to grasp unitedly it together with said dynode unit and said anode; and an upper
electrode having one or more slit grooves pinching a part of said pair of insulating support members and being attached to
said lower electrode in a state for said slit grooves to pinch a part of said pair of insulating support members.
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