Cosmic rays penetrating power

Now the penetrating power of the electrons knocked out of atoms by X-rays and gamma rays is very much smaller than that of the rays so that if cosmic rays were of the same nature as gamma rays—that is, if they were high energy photons—... 

Earth s atmosphere is constantly being bombarded by cosmic rays of extremely high penetrating power. These rays, which originate in outer space, consist of electrons, neutrons, and atomic nuclei. One of the important reactions between the atmosphere and cosmic rays is the capture of neutrons by atmospheric nitrogen (nitrogen-14 isotope) to produce the radioactive carbon-14 isotope and hydrogen. The unstable carbon atoms eventually form C02, which mixes with the ordinary carbon dioxide ( C02) in the air. As the carbon-14 isotope decays, it emits f3 particles (electrons). The rate of decay (as measured by the number of electrons emitted per second) obeys first-order kinetics. It is customary in the study of radioactive decay to write the rate law as... 

The nucleons consist mainly of photons, electrons, and positrons, and compose about 10 percent of the cosmic radiation at sea level. A fraction of muons and nucleons are absorbed while traversing the atmosphere. Variations in absorber thickness (air mass) are proportional to variations in barometric pressure. The absorption length for cosmic-ray muons at sea level in the atmosphere is 4,000 g/cm (Cocconl, 1951), and for cosmic nucleons, 120 g/cm (Hayakawa, 1969). Thus, it is clear that muons have significantly higher penetrating power than nucleons, about 33 times in the air. The probability of absorption rapidly increases with the atomic number, Z. In terms of lead shielding, these muons can penetrate a meter or more, while nucleons can be stopped in several inches of lead. 

The atmosphere of Earth is constantly being bombarded by cosmic rays of extremely high penetrating power. These rays, which originate in outer space, consist of electrons, neutrons, and atomic nuclei. One of the important reactions between the atmosphere and cosmic rays is the capture of neutrons by atmospheric nitrogen (nitrogen-14 isotope) to produce the radioactive carbon-14 isotope and hydrogen ... 

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