Reduction of Delay between Particle Passage and Spark Chamber Spark

The delay time between the passage of an ionizing particle and the spark-chamber spark is one of the limiting factors in the time resolution of spark-chamber systems. The usual resolving time is of the order of 0.5 μsec. The delay time in photomultipliers, cables, coincidence mixers, high voltage pulse generators, spark gaps, spark chamber voltage rise, and spark formation is investigated. Elements of a system are described which result in a total delay of about 33 nsec, including the photomultiplier. This may permit a reduction in spark chamber memory time and time resolution by about one order of magnitude. The reduction in delays and rise times also decreases the displacement of tracks in spark chambers operating in a magnetic field.