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Cosmogenic radiation


Radioactivity measurement

High-energy particles from the galaxis and sun, especially protons (70%) and helium nuclei (20%) but also a very small proportion of gamma radiation, hit the earth atmosphere. A number of nuclear reactions occur mainly in the upper layers of the atmosphere at a height of about 25 km and below. The main source of the mean radiation exposure of about 0.3 mSv per year measured at sea level is short-lived, highly penetrating muons as well as electrons and neutrons. Near the earth, the absorbed dose rate of 0.035 µSv/h increases with altitude, doubling every 1500 m. In aircraft, absorbed dose rates of 8 µSv/h have been measured at 12 km altitude in middle latitudes.

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What is radioactivity?


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If you have any additional questions, please e-mail Dr. Jürgen Herrmann or phone +49 40 3190 - 3325


More information on the subject:
MARNET monitoring system

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 © 2016 Bundesamt für Seeschifffahrt und Hydrographie Last Update: Apr 19, 2013 6:01:23 PM  
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