Poster Presentation

Cosmic Ray Air Shower Lateral Coincidences

  • Gordon McIntosh (University of Minnesota, Morris)


At the University of Minnesota, Morris, my students and I have begun to investigate the time and altitude dependence of air showers. Air showers are cosmic ray secondaries that spread out laterally around the primary cosmic ray direction. To investigate the air showers we have been measuring the lateral coincidences among three Aware RM60 Geiger counters located at 0 cm, 15 cm, and 40 cm. Most of these measurements have been carried out at the surface. The rate of lateral, triple coincidences of Geiger counter with this configuration is 0.053 ±0.013 hr-1 at the surface. On 4 April 2015 the UMM Modern Physics class made a balloon launch that included a measurement the lateral, triple coincidence versus altitude. Three triple coincidences were measured during the 1.75 hour flight. The rate of triple coincidences was 1.7±1.0 hr-1. This rate is ~30 times the rate measured at the surface and indicates that showers of sufficient lateral extension to produce triple coincidences occur at a greater rate at higher altitudes.

How to Cite:

McIntosh, G., (2015) “Cosmic Ray Air Shower Lateral Coincidences”, Academic High Altitude Conference 2015(1). doi:



Published on
19 Jun 2015
Peer Reviewed