A System for Multiparameter Pulse Height Analysis with Repeated Use of a Single, Fast ADC

In many nuclear physics experiments an event consists of correlated output pulses from several radiation detectors. We call each separate output pulse a parameter. The experiments with which we are dealing are multiparameter experiments. We have constructed a system in which a single ADC is interfaced to a general purpose computer. Multiparameter experiments are handled by storing the several pulses in analog stretchers and using the ADC repeatedly to digitize the several pulses in sequence. This approach is made practical by the availability of a very fast ADC. The system includes features that give it unusual flexibility for handling complicated time relationships among the pulses. The use of one rather than several ADC's makes the system simpler, more compact, and less expensive than multiple ADC systems. Provisions are included for evaluating counting loss due to dead time of the system for random or non-random event distributions. The data transfer logic incorporates the facility for including digital information from devices in addition to the ADC in each event datum.