Slide Title: Cosmic Rays-what are they?

Slide Words:
Charged (ionized) atomic nuclei from space
Composed of hydrogen (protons) through iron
Same abundances as in the solar system
Energies from < 106 eV to > 3x1020 eV (50 joules)
Enter the atmosphere from all directions
Collide with air molecules in the upper atmosphere
1020 eV cosmic rays produce a shower of 1011 particles on the ground
About 200 secondary particles (muons)/meter2/second at sea level
About 10% of natural radiation exposure (including dental X-rays)
Congress cannot outlaw this source of radiation

Slide Source: NSF and James Cronin