About Cosmic Ray Monitor


The PARI Cosmic Ray Monitor uses two RM-70 Geiger Counters (Aware Electronics) running in coincidence mode.

Cosmic Rays are ionized particles from space which enter the atmosphere and produce a cascade of secondary particles (primarily muons).

Muons are detected in coincidence mode and must pass throught two detectors to determine direction of flight.


Background activity is the sum of naturally occuring radiactive compounds in the soil, Radon gas, and random electrical noise.

The monitor is located at Pisgah Astronomical Research Institute, near Rosman, NC at

  • Latitude +35 deg 11.8 min N
  • Longitude  82 deg 52.3 min W
  • Surface Altitude: 933 m or 3060 feet


  • Links:

    Aware Electronics
    North American Large area Time coincidence Arrays
    Building the Cosmic Ray Telescope
    Scintillation Counters

    email Dr. Joe Phillips at: jfp@wmed.com


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