| 摘要 |
PURPOSE:To effectively shield the thermoelectrons emitted from a photoelectric face and improve the detection precision of photoelectrons by setting the position of a support pin nearest to the electrode support pin of a photoelectron emitting electrode plate and within a range that the incident light is not cut off by the shape of a metal plate. CONSTITUTION:A thermoelectron shielding metal plate 17 is provided between a photoelectron emitting electrode plate 6 and the first dynode 7 to block the effect of the thermoelectrons emitted from a photoelectric face and improve the detection precision of the light, i.e., S/N. The position of a support pin is on the line LN connecting the electrode support pin 23 of the second dynode 8 and the electrode support pin 21' of the photoelectron emitting electrode plate 6. The cross section shape of the metal plate 17 is formed nearly to follow the equipotential plane, thus the electrons emitted from the photoelectron emitting electrode plate 6 can pass the opening 33 of the metal plate 17 in the nearly vertical direction to the metal plate 17, and the probability that photoelectrons reach the dynode 7 can be improved.
|
