Real time neutron monitor

http://ulysses.sr.unh.edu/NeutronMonitor/Misc/neutron2.html

Ground level neutrons are produced from secondary nuclear reactions occuring from primary cosmic rays hitting atmospheric atomic nuclei. The first neutron monitors were created as a result of John Simpson and his cosmic ray research at Chicago.

http://www.ngdc.noaa.gov/stp/SOLAR/COSMIC_RAYS/cosmic.html

Data table for 2004 at Climax, CO: ftp://ulysses.sr.unh.edu/NeutronMonitor/HourlyClimax/Climax2004