Millimicrosecond Timing with Large Scintillation Detectors

Abstract

The timing precision attainable with large liquid scintillation detectors has been studied. Such detectors have slow rise-times (∼10−8 sec) compared with those used in conventional nuclear physics timing experiments. The rise-time is a result of photon time of flight and transit time in the larger, slower photomultipliers (such as the Dumont 6364) which must be used for good light collection. However, timing errors due to rise-time may be largely overcome when dealing with large, statistically smooth pulses such as are encountered in cosmic-ray experiments with unstable particles. A simple correction based on the pulse height is applied to each time measurement. Using this technique a timing error curve is obtained with a standard deviation of 1.6 mμsec for a large detector using a Dumont 6364.