Self-limiting photomultiplier amplifier circuit

Claim 1

A PHOTOMULTIPLIER AMPLIFIER CIRCUIT COMPRISING A PHOTOMULTIPLIER AMPLIFIER TUBE HAVING AS ELECTRODES AN ANODE, A CATHODE AND A PLURALITY OF DYNODES, SAID PHOTOMULTIPLIER AMPLIFER TUBE BEING SUBJECT TO LIMITING OF ELECTRON CURRENT FLOW IN AN INTERELECTRODE SPACE THEREOF IN RESPONSE TO A POTENTIAL DIFFERENCE BETWEEN THE FINAL DYNODE AND AN ADJACENT ELECTRODE WHICH IS LESS THAN A FIRST VALUE, A SOURCE OF BIAS POTENTIAL HAVING A PLURALITY OF TAPS, MEANS COUPLING SAID CATHODE, SAID ANODE AND SAID DYNODES TO SELECTED TAPS ON SAID BIAS SOURCE, SAID MEANS COUPLING SAID ANODE TO SAID BIAS SOURCE INCLUDING MEANS FOR DERIVING AN OUTPUT SIGNAL FROM SAID AMPLIFER CIRCUIT, SAID BIAS SOURCE INCLUDING MEANS FOR CAUSING SAID TAPS TO BE AT DIFFERENT POTENTIALS, SAID LAST MENTIONED MEANS CAUSING THE POTENTIAL DIFFERENCE BETWEEN THE SAID TAPS CONNECTED TO SAID FINAL DYNODE AND SAID ADJACENT ELECTRODE TO BE SUBSTANTIALLY LESS THAN THE POTENTIAL DIFFERENCE BETWEEN TAPS ASSOCIATED WITH OTHER ADJACENT ELECTRODES OF SAID PHOTOMULTIPLIER AMPLIFIER TUBE AND LESS THAN SAID FIRST VALUE.