Abstract A photomultiplier tube comprising a plurality of electrodes including a light sensitive cathode, an anode, and a plurality of dynodes positioned in space-apart manner along the electron beam path between the cathode and anode and having a power supply and a voltage divider for supplying bias voltages across each successive pair of electrodes along the beam path, at least one switching device being provided across a pair of said electrodes, preferably across the cathode and first dynode or across the first and second dynodes, which, when activated, will rapidly reduce the bias voltage across the associated pair of electrodes to near zero, thereby substantially reducing the sensitivity of the multiplier to protect it from the effects of excessive light intensity input. In a preferred embodiment of the invention, an SCR is coupled across the cathode and first dynode and is operated by a blanking or trigger pulse applied to its control gate to rapidly reduce the bias voltage across this first stage. Additional switching rectifiers may be employed across other stages of the multiplier to insure the desired reduction in sensitivity.
Inventors
👤 Clenahan J Mc
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-03 22:23
CPC Classifications
H; H01; H01J; H01J43/00; H01J43/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
140 words
A photomultiplier device comprising a plurality of electrodes arranged in sequential manner along an electron beam path therethrough and including a light sensitive cathode, an anode, and a plurality of dynodes positioned in spaced-apart manner between the cathode and anode, means including a power supply for providing bias voltage across successive pairs of said electrodes, a first switching rectifier coupled between said cathode and the first dynode in the path between said cathode and said anode, a second switching rectifier coupled between the said first dynode and the second dynOde in the path between said cathode and said anode, and means for at times activating said first and second rectifiers to turn off the device by reducing the voltage between the electrodes connected to said rectifiers to substantially zero and thereby reducing the sensitivity of the photomultiplier to substantially zero.
Claim 2
Dependent Claim
140 words
A photomultiplier device comprising a plurality of electrodes arranged in sequential manner along an electron beam path therethrough and including a light sensitive cathode, an anode, and a plurality of dynodes positioned in spaced-apart manner between the cathode and anode, means including a power supply for providing bias voltage across successive pairs of said electrodes, a first switching rectifier coupled between said cathode and the first dynode in the path between said cathode and said anode, a second switching rectifier coupled between the said first dynode and the second dynOde in the path between said cathode and said anode, and means for at times activating said first and second rectifiers to turn off the device by reducing the voltage between the electrodes connected to said rectifiers to substantially zero and thereby reducing the sensitivity of the photomultiplier to substantially zero.