Heavy Primary Cosmic Radiation at the Equator

Abstract

The zenith and azimuthal angular distribution of primary cosmic rays with charges \ensuremath{\geqq} 6 has been measured at the equator using oriented nuclear emulsions. The magnitude of the azimuthal asymmetry is consistent with an integral power law spectrum which falls off inversely as the 2.0 power of the total energy per nucleon. However, the maximum intensity comes from the southwest rather than the west. This is consistent with the recently proposed shift of the earth's effective magnetic field for cosmic rays.The flux at the top of the atmosphere is 0.68 particle ${\mathrm{m}}^{\ensuremath{-}2}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ ${\mathrm{sterad}}^{\ensuremath{-}1}$ for CNOF (carbon, nitrogen, oxygen, fluorine) nuclei and 0.21 particle ${\mathrm{m}}^{\ensuremath{-}2}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ ${\mathrm{sterad}}^{\ensuremath{-}1}$ for nuclei with $Z\ensuremath{\geqq}10$.