Factors and processes controlling the concentration of the cosmogenic radionuclide 7Be at high-altitude Alpine stations

Publisher Summary 7Be is a cosmogenic radionuclide with radioactive decay half-life of 53.3 days and it is a naturally occurring gamma emitter (477.6 keV). The bombardment of atmospheric constituents by cosmic rays (CR) leads to the fragmentation of light atmospheric nuclei, primarily 12C, 14N and 16O, thus giving rise to the production of various cosmogenic isotopes. Neutrons and protons, produced in about equal numbers as a result of the nucleonic cascade initiated near the top of the atmosphere by the most energetic primary component of cosmic radiation, are mainly responsible for nuclear disintegrations in the atmosphere. Low-energy interactions by nucleons with energies of 100–200 MeV have the largest contribution to the isotope production. Since protons experience intense and rapid loss of their energy due to ionization, the production of the majority of radionuclides is attributed to neutrons.