The Energy Spectrum of Primary Cosmic Radiation

Techniques have been developed by which the energy spectrum of heavy primary nuclei can be measured in the energy range of ${10}^9$-${10}^{11}$ ev/nucleon and of both protons and $\alpha$-particles in the energy range from ${10}^{11}$ to ${10}^{13}$ ev/nucleon. It is shown that even the heaviest nuclei in the primary radiation ($Z\sim 26$) have lost their orbital electrons before entering the atmosphere, which supports the assumption that they do nor proceed from the solar corona directly to the earth. It is also shown that the velocity spectrum of all primaries of charge $Z>\mathrm{}1\mathrm{}$ is independent of the mass of the nuclei, and that it differs only slightly from that of the proton component in the energy interval between 3×${10}^8$ and ${10}^{10}$ ev/nucleon.