A 25‐Input Pulse‐Height Recording System

A general description is given of a data recording system which provides a link between counter experiments in high-energy physics and a high-speed digital computer. The instrument described can accept as many as 25 simultaneous photomultiplier tube signals and pulse height analyze them into 100 channels each. Six bits of digital data may be substituted for any unused pulse height input. The usual output is perforated paper tape with a binary coded decimal format for use with a Burroughs 220 computer. Identification words can be set up and recorded on the tape. The speed of the paper tape perforator limits the rate of analysis to one event per second. If the output data is fed directly into a computer memory, then the recording rate can be increased to 60 events per second. The instrument has been in operation since December 1961, and results obtained with it using both particles produced by the Caltech Synchrotron and pulsers are given. Only solid state components have been used, including nearly 1700 transistors and an equal number of diodes.