Pulse-to-Analog Converter for Optimizing Signal-to-Noise from Photomultipliers at Low Light Intensities

Abstract

A simple circuit is presented which is designed to discriminate and shape pulses from photomultiplier tubes and to provide an output suitable for analog recording. This circuit may readily be inserted between the photomultiplier and existing analog signal processing equipment. Signal‐to‐noise measurements are given for a cooled photomultiplier, with and without the pulse shaping circuitry. This circuitry affords a significant gain in the signal‐to‐noise ratio for a cooled phototube under conditions of low light flux when used in an analog system. We have found that the resulting signal‐to‐noise is governed by counting statistics alone.