Linearitätsabweichungen bei Strahlungsmessungen mit Photovervielfachern.
Sources of nonlinear response of photomultiplier tubes are discussed, and examples are given for conditions where nonlinearities >10(-3) are possible. Slow fatigue nonlinearities were eliminated by a beat technique; the results therefore should be applicable to measurements of pulsed radiation at low or constant mean level. Nonlinearities caused by current takeover from a resistive voltage divider were compared with calculations. Reasons of inner nonlinearities were space charges: (a) between cathodexand first dynode (at cathode currents >10(-9) A, depending on cathode spot and wavelength) and (b) between the last dynodes. Up to approximately l-mA anode current proportionality was observed between currents and nonlinearities. Avoiding fatigue by pulsed operation, the range of linear response may be much expanded compared with dc operation.
Sauerbrey
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