New light on the nature and origin of the incoming cosmic rays

Cosmic-ray electrons enter the atmosphere only in a definitely limited and relatively narrow energy range. The maximum of this energy distribution curve lies at about 6 billion e-volts. At 1 billion e-volts the curve has fallen to about a third of its maximum value, and on the other side of the maximum at some 17 billion e-volts the incoming energy also has about a third of its maximum value. The observed banded structure may possibly be partly due to the blocking effect of the sun's magnetic field on electrons trying to pass through it to the earth. The total cosmic-ray energy brought in by electrons of energy above 17 billion e-volts plus all that brought in by photons of all energies is about the same as the energy brought in by electrons alone of energies between 6 and 17 billion e-volts, and this energy is fully twice that brought in by all entering electrons of energies less than 6 billion e-volts. The smallness of the fraction of the total incoming energy that can be assigned to photons shows that the cosmic rays cannot ever have come through an appreciable amount of matter in comparison with an atmosphere before entering the solar system. The energies of the incoming rays correspond roughly to the annihilation energies of the atoms of the most abundant elements