GAIN STABILIZATION OF PHOTOMULTIPLIERS

摘要

A self-stabilizing scintillation detector system for the measurement of nuclear radiation, preferably gamma radiation, is provided, the system comprising a scintillation crystal, a photo detector, a photomultiplier (PMT) with n dynodes and an evaluation system connected to the output port of the PMT, i.e. the anode of the PMT, the PMT comprising at least two connections to at least two different dynodes of the PMT, a device for measuring the electric current at the at least two dynodes, as well as an electronic device for determining the quotient of the measured at least two electric currents at the at least two dynodes, said quotient being a measure for the gain between the two dynodes, further comprising means for comparing the measured quotient with a reference value, and means for adjusting the gain of the PMT by utilizing the gain change over time.

主权项

1. A self-stabilizing scintillation detector system for the measurement of nuclear radiation, preferably gamma radiation, comprising:
a scintillation crystal, a photo detector, a photomultiplier (PMT) with n dynodes and an evaluation system connected to the output port of the PMT, i.e. the anode of the PMT, the PMT comprising at least two connections to at least two different dynodes m1 and m2 of the PMT, a device for measuring the electric current Idyn1 and Idyn2 at the at least two dynodes m1 and m2, as well as an electronic device for determining the quotient δ of the measured at least two electric currents Idyn1 and Idyn2 at the at least two dynodes, said quotient δ being a measure for the gain between the two dynodes, further comprising means for comparing the measured quotient δ with a reference value δREF, and means for adjusting the gain of the PMT by utilizing the gain change over time.