| 主权项 |
1. A photomultiplier tube comprising:
a photocathode having a first surface for receiving light and a second surface opposite the first surface from which electrons are emitted in response to light that is incident on the first surface; an electron multiplying device positioned in spaced relation to said photocathode, said electron multiplying device having an electron receiving side that faces the second surface of said photocathode and an electron emission side opposite the electron receiving side, said electron multiplying device being positioned such that the electron receiving side is located at a preselected distance from the second surface of said photocathode; a first electrode operatively connected to the electron receiving side of said electron multiplying device; a second electrode operatively connected to the electron emission side of said electron multiplying device; an ion suppression electrode positioned between said photocathode and said electron multiplying device and spaced therefrom, said ion suppression electrode comprising a grid that is configured to provide sufficient rigidity to avoid deformation during operation of the photomultiplier tube; and a source of electric potential connected to said second electrode and to said ion suppression electrode, said electric potential source being adapted to provide a first voltage to said second electrode and a second voltage to said suppression grid electrode wherein the second voltage has a magnitude equal to or greater than the magnitude of the first voltage. |
