Energetic radiation observations near meter-scale sparks in the laboratory

The discovery that ordinary laboratory sparks produce x-rays implies the existence of a population of energetic electrons. These electrons may be produced by streamers or interaction of streamer systems, but their exact production mechanism and properties are not well-known. We report on experiments designed to measure x-rays and energetic electrons at a variety of positions near meter-long sparks. The detectors used are coupled by fiber optics to a well-shielded data acquisition system and can be placed quite near to the spark or electrodes. The results suggest variability in observations is due to a combination of variability from one spark to the next and strong spatial variability from one location to another within a single spark. Specific examples and statistical analysis will be presented.