The stability of a photomultiplier at high counting rates required the use of a low-resistance voltage divider for the last few dynodes. This has been achieved by means of a transistor circuit that stabilizes the potentials of the last three dynodes by comparison with the corresponding potential of an unloaded resistance voltage di¬vider. The dynode voltages can thus be varied over a wide range. The temperature dependence of the elements has been practically eliminated by means of a symmetrical circuit design.
展开▼
