Protective circuitry for photomultiplier tubes
AssigneeLeica Microsystems CMS GmbH
InventorJuergen Schneider
Life of this patent
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Abstract
An electronic circuit for protecting a photomultiplier against overloads is provided. The photomultiplier has a cathode, an anode, a plurality of dynodes and a voltage divider. The circuit includes a high-voltage source, which applies a high voltage to the photomultiplier. A protective switch is set up for preventing a current flow through the anode. A comparison device is configured for comparing a load signal characterizing the loading of the anode with a maximum load signal and for driving the protective switch in accordance with this comparison.
Claims18
An electronic circuit for protecting a photomultiplier against overloads, the photomultiplier receiving a high voltage from a high voltage source, and having a cathode, an anode, a plurality of dynodes, and a voltage divider, the electronic circuit comprising:
- a protective switch operatively configured to prevent a current flow through the anode;
- a comparison device operatively configured for comparing a load signal characterizing loading of the anode with a maximum load signal, an output of the comparison device driving the protective switch as a function of the comparison;
- and
- wherein the protective switch is set up for acting on a reference potential of the voltage divider.
A scanning microscope for examining a sample, comprising:
- at least one light source for generating at least one microscope beam which acts upon the sample;
- at least one scanning device for scanning the sample with the microscope beam;
- at least one photomultiplier for detecting light emitted, reflected, and/or transmitted by the sample;
- and
- at least one electronic circuit for protecting the photomultiplier against overloads, the photomultiplier being supplied with high voltage via a high voltage source and having a cathode, an anode, a plurality of dynodes and a voltage divider;
- wherein the electronic circuit further comprises a protective switch operatively configured to prevent a current flow through the anode;
- a comparison device operatively configured for comparing a load signal characterizing loading of the anode with a maximum load signal and driving the protective switch as a function of the comparison;
- and
- wherein the protective switch is set up for acting on a reference potential of the voltage divider.
A method for protecting a photomultiplier against overloads, the photomultiplier having a cathode, an anode, a plurality of dynodes and a voltage divider, the method comprising the acts of:
- applying a high voltage to the photomultiplier via a high voltage source;
- comparing a load signal characterizing a loading of the anode with a maximum load signal;
- and
- preventing current flow through the anode via a protective switch when the maximum load signal is exceeded, wherein the protective switch is set up for acting on a reference potential of the voltage divider.
Dependencies are inferred from the claim text.