Properties of the Low Energy Nucleonic Component at Large Atmospheric Depths

This is a report on the absorption properties of the cosmic radiation low energy nucleonic component measured by detectors of disintegration product neutrons as the nucleonic cascade develops deep within the atmosphere. The air absorption mean free path $L$ of the star- or neutron-producing radiation was measured as a function of atmospheric depth $x$ (in g-${\mathrm{cm}}^{-2\mathrm{}}$ atmosphere) at the geomagnetic latitudes $\lambda =0\mathrm{}°, 41°, 52°$. $L(x, \lambda )$ was obtained for carbon or free atmosphere and for a lead plus carbon pile geometry. As reported earlier, for small $x$ the absorption mfp, L, is dependent upon $\lambda$ ($L$ is a function of the average energy of the primary nucleons which initiate the nucleonic chain or cascade). However, it is shown by the present measurements that, for $x>\mathrm{}600\mathrm{}$ g-${\mathrm{cm}}^{-2\mathrm{}}$, $L\to \sim 140$ g-${\mathrm{cm}}^{-2\mathrm{}}$ independent of latitude $\lambda$.