The on-line computer counter and digitalized spark-chamber technique

In the fall of 1962 at the Brookhaven Alternating Gradient Synchrotron, a remarkable event took place. A highly complex elastic‐scattering experiment involving high‐energy $\text{(7–20\hspace{0.17em}}\mathrm{BeV}\mathrm{/c)}$ protons and pions scattered by a hydrogen target was investigated by a system of several hundred scintillation‐counter hodoscopes covering a large fraction of the solid angle in the investigated angular region. The system was all in fast (a few to 30 nsec) coincidence with complicated‐logic trigger requirements, and it automatically trigger‐selected, compiled, stored, and finally transmitted the data to an on‐line computer. The computer then processed the data automatically and rapidly in real time according to a carefully pre‐programmed analysis, stored the desired results in suitable bins, and transmitted the program‐requested data displays back to the display scopes of the experimental group. Desired physical answers based on cumulative statistics (such as computed cross sections, errors, background values and distribution, displays of counter‐efficiency uniformity, etc.) were also available in detailed print‐out tabular (or, if desired, graphical) form, upon initiation by the experimenters of a simple output routine.