A Pulse Analyser for Nuclear Research

Abstract

One method of determining particle energies in nuclear research depends upon the measurement of pulses produced by the particles in an ionization chamber. The Pulse Analyser is an instrument which analyses the electrical pulses from the chamber into a number of classes according to their amplitude and hence produces an energy spectrum of the particles. It has the following features: (1) every pulse is counted ensuring the highest accuracy for a given time; (2) some indication of the final result appears while the experiment is in progress; (3) the number of pulses within a certain amplitude range is recorded by a mechanical counter, eliminating most of the labor required for obtaining results. Problems of design are discussed, and a brief survey of the ways in which they are treated in five different Pulse Analysers is given. One of these instruments, built by the authors, is described in detail. This Analyser is designed for slowly rising pulses (up to 1 millisecond in duration) and for low counting rates (up to a few hundred per minute). It has 20 identical channels, each channel recording the pulses within an amplitude range that can be varied from 0.1 to 10 volts. The performance of the Analyser is discussed and some typical results obtained with it are given.