On the Azimuthal Asymmetry of Cosmic-Ray Intensity above the Atmosphere at the Geomagnetic Equator

By means of Geiger-Mueller tube telescopes in an Aerobee sounding rocket fired to high altitude at the geomagnetic equator, information on the azimuthal asymmetry of the cosmic-ray intensity above the atmosphere has been obtained. These results, in conjunction with previously reported vertical intensities and specific ionizations at λ=0^∘ and λ=41^∘N, are consistent with the hypothesis that most of the primaries are positively charged protons with differential number spectrum of the form dN=KE^-1.9dE in the energy region 5 to 23 Bev.