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 $\lambda =0\mathrm{}°$ and $\lambda =41\mathrm{}°$N, are consistent with the hypothesis that most of the primaries are positively charged protons with differential number spectrum of the form $dN=K{E}^{-1.9\mathrm{}}\mathrm{dE}$ in the energy region 5 to 23 Bev.