Potential of Small Digital Computers for Analyzing Nuclear Spectroscopy Data

The development of larger, more accurate analog-to-digital converters and high resolution detectors has given rise to many new problems in the acquisition and analysis of data. This paper will present examples of how these problems have been approached using a small computer (DEC PDP-8). Although the examples to be presented deal with gamma-ray spectra, the techniques used should be applicable to beta or particle spectra. The major problems presently associated with the analysis of gamma-ray spectra are centered around the large volumes of data accumulated in a typical experiment. Large amounts of time elapse when these data are analyzed on a large computer in a batch-type operation. The time loss is not in the actual computing time, but in the formating of data, large turn-around times, and correlating information in listings and plots of the data. All of these bottlenecks have been either substantially reduced or eliminated by using the small computer connected to an oscilloscope and light pen. The spectrum is stored in the computer memory and can be displayed and manipulated in many different ways by using sense switch operations plus the concept of an electronic keyboard on an oscilloscope. This system allows an experimenter to determine transition energies, photopeak intensities, etc., in one setting as opposed to time lapses of as great as two weeks under previous conditions. Thus delays due to turn-around times, listing and plotting, and correlating information on the lists and plots have been eliminated.