Variations of cosmogenic radionuclide production rates in chondrites of known orbits

The results of multiyear investigations of cosmogenic radionuclide production rates along the orbits of 42 chondrites, fallen successively to the Earth in 1959-2016 are presented. They constitute a long set of homogeneous data, statistical smoothing of which demonstrates some main regularities of distribution and variation of the galactic cosmic rays (GCR) with energy > 100 MeV in the internal (< 5 AU) heliosphere. This set is exclusive, and it has timeless importance for all the future investigations of magneto-hydrodynamic peculiarities of the GCR solar modulation mechanism. Analysis of ²⁶Al contents in 10 chondrites of known orbits allowed us to educe a spatial profile of the GCR intensity (E > 100 MeV), averaged over a 1 My in the internal heliosphere, testifying to permanent development and dissipation of a layer of the solar wind magnetic irregularities, which efficiently modulates cosmic radiation. It suggests a constancy of magneto-hydrodynamic environment in the Solar system at least for the last million years.